IEC 62841-3-4:2016

IEC 62841-3-4 ®
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electric motor-operated hand-held tools, transportable tools and lawn and
garden machinery – Safety –
Part 3-4: Particular requirements for transportable bench grinders

Outils électroportatifs à moteur, outils portables et machines pour jardins et
pelouses – Sécurité –
Partie 3-4: Exigences particulières pour les tourets à meuler transportables

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IEC 62841-3-4 ®
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electric motor-operated hand-held tools, transportable tools and lawn and

garden machinery – Safety –
Part 3-4: Particular requirements for transportable bench grinders

Outils électroportatifs à moteur, outils portables et machines pour jardins et

pelouses – Sécurité –
Partie 3-4: Exigences particulières pour les tourets à meuler transportables

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.140.20 ISBN 978-2-8322-3204-0

– 2 – IEC 62841-3-4:2016 © IEC 2016
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references. 6
3 Terms and definitions . 6
4 General requirements . 7
5 General conditions for the tests . 7
6 Radiation, toxicity and similar hazards . 7
7 Classification . 7
8 Marking and instructions . 7
9 Protection against access to live parts . 9
10 Starting . 9
11 Input and current . 9
12 Heating . 9
13 Resistance to heat and fire . 9
14 Moisture resistance . 9
15 Resistance to rusting . 9
16 Overload protection of transformers and associated circuits . 9
17 Endurance . 10
18 Abnormal operation . 10
19 Mechanical hazards . 10
20 Mechanical strength . 14
21 Construction . 16
22 Internal wiring . 17
23 Components . 17
24 Supply connection and external flexible cables and cords . 17
25 Terminals for external conductors . 17
26 Provision for earthing . 17
27 Screws and connections . 17
28 Creepage distances, clearances and distances through insulation . 17
Annexes . 22
Annex I (informative) Measurement of noise and vibration emissions . 22
Bibliography . 23

Figure 101 – Bench grinder . 18
Figure 102 – Opening angles and dimensions for a guard . 19
Figure 103 – Transparent screen . 20
Figure 104 – Bench grinder with inclinable work rest . 20
Figure 105 – Flange dimensions . 21

Table 4 – Required performance levels . 10
Table 101 – Minimum flange dimensions (see Figure 105) . 13

Table 102 − Test torque for flanges . 13
Table 103 − Guard thickness for steel . 15
Table 104 − Guard thickness for aluminium . 15
Table 105 – Minimum tool spindle diameter . 16
Table I.101 – Operating conditions for bench grinders . 22

– 4 – IEC 62841-3-4:2016 © IEC 2016
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRIC MOTOR-OPERATED HAND-HELD TOOLS, TRANSPORTABLE
TOOLS AND LAWN AND GARDEN MACHINERY –
SAFETY –
Part 3-4: Particular requirements for transportable bench grinders

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62841-3-4 has been prepared by IEC technical committee 116:
Safety of motor-operated electric tools.
The text of this standard is based on the following documents:
FDIS Report on voting
116/258/FDIS 116/275/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

This Part 3-4 is to be used in conjunction with the first edition of IEC 62841-1:2014.
This Part 3-4 supplements or modifies the corresponding clauses in IEC 62841-1, so as to
convert it into the IEC Standard: Particular requirements for transportable bench grinders.
Where a particular subclause of Part 1 is not mentioned in this Part 3-4, that subclause
applies as far as relevant. Where this standard states “addition”, “modification” or
“replacement”, the relevant text in Part 1 is to be adapted accordingly.
The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
The terms defined in Clause 3 are printed in bold typeface.
Subclauses, notes and figures which are additional to those in Part 1 are numbered starting
from 101.
A list of all parts of the IEC 62841 series, under the general title: Electric motor-operated
hand-held tools, transportable tools and lawn and garden machinery – Safety, can be found
on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 36 months from the date of publication.
The contents of the corrigendum of December 2016 have been included in this copy.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – IEC 62841-3-4:2016 © IEC 2016
ELECTRIC MOTOR-OPERATED HAND-HELD TOOLS, TRANSPORTABLE
TOOLS AND LAWN AND GARDEN MACHINERY –
SAFETY –
Part 3-4: Particular requirements for transportable bench grinders

1 Scope
This clause of Part 1 is applicable, except as follows:
Addition:
This part of IEC 62841 applies to transportable bench grinders that can be equipped with
one or two accessories as follows:
– type 1 grinding wheels in accordance with ISO 603-4:1999 with a diameter not exceeding
310 mm and a thickness not exceeding 55 mm;
– wire brushes with a diameter not exceeding 310 mm and a thickness not exceeding
55 mm;
– polishing wheels with a diameter not exceeding 310 mm;
and with a peripheral speed of any accessory between 10 m/s and 50 m/s.
NOTE Polishing wheels are also known as buffing wheels.
2 Normative references
This clause of Part 1 is applicable, except as follows:
Addition:
ISO 603-4:1999, Bonded abrasive products – Dimensions – Part 4: Grinding wheels for
surface grinding/peripheral grinding
3 Terms and definitions
This clause of Part 1 is applicable, except as follows:
3.101
bench grinder
tool designed to grind, clean, polish or debur metal or similar materials by means of one or
two rotating accessories fixed to one or two tool spindles, see Figure 101, where the
workpiece is held by hand and possibly assisted by a work rest
3.102
tool spindle
drive spindle of a bench grinder which supports the accessories and provides the rotation
3.103
work rest
surface or device intended to support or to guide the workpiece

4 General requirements
This clause of Part 1 is applicable, except as follows:
4.101 D is understood to be the maximum diameter of the accessory to be used on each
tool spindle. Unless otherwise specified, tool spindle specific requirements dependent on D
shall be based on the value of D for the relevant tool spindle.
Throughout the remaining part of this document, unless otherwise explicitly stated, whenever
a requirement or a reference is made to “force” as multiple of D, the force shall be expressed
in newtons (N) and D shall be expressed in millimetres (mm).
5 General conditions for the tests
This clause of Part 1 is applicable, except as follows:
5.17 Addition:
The mass of the tool shall include the guards, work rests and transparent screens. Any
additional parts such as leg sets or carrying means that are required in accordance with the
instructions for the safe use of the tool shall be included in the mass.
6 Radiation, toxicity and similar hazards
This clause of Part 1 is applicable.
7 Classification
This clause of Part 1 is applicable.
8 Marking and instructions
This clause of Part 1 is applicable except as follows:
8.1 Addition:
Tools shall be marked with:
– rated no-load speed of the tool spindle(s).
8.2 Addition:
Tools shall be marked with the following safety warnings:
– “ WARNING Always wear eye protection” or the symbol M004 of ISO 7010 or the
following safety sign:
– a warning near any polishing spindle (i.e. a spindle without a guard) never to use a
grinding wheel or wire brush on the polishing side of the tool, if applicable.

– 8 – IEC 62841-3-4:2016 © IEC 2016
8.3 Addition:
Bench grinders shall be marked with the minimum and maximum diameter of the accessory
to be used on each tool spindle.
Bench grinders shall be marked with the direction of rotation of the tool spindle, indicated in
a visible location on the tool in the vicinity of the tool spindle, by an arrow raised or recessed
or by any other means no less visible and indelible.
8.14.1 Addition:
The additional safety instructions as specified in 8.14.1.101 shall be given. This part may be
printed separately from the “General power tool safety warnings”.
8.14.1.101 Safety instructions for bench grinders
Bench grinder safety warnings
a) Do not use a damaged accessory. Before each use, inspect the accessory such as
abrasive wheels for chips and cracks and wire brushes for loose or cracked wires.
After inspecting and installing an accessory, position yourself and bystanders away
from the plane of the rotating accessory and run the power tool at maximum no-load
speed for one minute. Damaged accessories will normally break apart during this test
time.
NOTE 1 For tools that are not intended for wire brushes, the phrase “and wire brushes for loose or cracked
wires” is omitted.
b) The rated speed of the accessory must be at least equal to the maximum speed
marked on the power tool. Accessories running faster than their rated speed can break
and fly apart.
c) Be aware that wire bristles are thrown by the wire brush even during ordinary
operation. Do not overstress the wires by applying excessive load to the wire brush.
The wire bristles can easily penetrate light clothing and/or skin.
NOTE 2 The above safety warning applies only to tools intended to be used with wire brushes.
d) Never grind on the sides of a grinding wheel. Grinding on the side can cause the wheel
to break and fly apart.
8.14.2 a) Addition:
101) Information about details and type of the accessory(ies) recommended for each tool
spindle, e.g. the maximum thickness of the accessory and the diameter of the hole in
the accessory;
102) Instruction to use only accessories with a diameter according to the relevant marking
as required by 8.3;
103) Instruction to ensure that the bench grinder is always stable and secure (e.g. fixed to
a bench) and instruction how to fix the tool to a workbench or the like;
104) Instructions on the correct mounting of wheels and ensuring that wheels are free of
defects before use, including instructions for performing a ring test for cracks.
8.14.2 b) Addition:
101) Instruction to adjust the spark arrestor and the work rest frequently so as to
compensate for wear of the wheel;
102) Instruction to keep the distance between the spark arrestor/work rest and the wheel
as small as possible and in any case not greater than 2 mm;
103) Instruction to replace the worn wheel when these gaps are no longer able to be
maintained;
104) For tools with two spindles: instruction to always use the tool with accessories on both
spindles in order to limit the risk of contact with the rotating spindle;
105) Instruction to always use the guard, work rest, transparent screen and spark arrestor
as required for the accessory(ies);
106) For tools with a vertically adjustable or inclinable work rest: instruction on how to
properly adjust and secure the work rest angle in relation to the wheel;
107) Instructions on how to perform grinding functions safely;
108) Instruction to replace damaged or deeply grooved wheels;
109) Instruction where to lift and support the bench grinder during transportation;
110) Instruction to always adjust the work rest so that the angle between the work rest and
the tangent of the accessory is always greater than 85°.
8.14.2 c) Addition:
101) Instructions for handling and storage of grinding wheels and wire brushes, if
applicable.
9 Protection against access to live parts
This clause of Part 1 is applicable.
10 Starting
This clause of Part 1 is applicable.
11 Input and current
This clause of Part 1 is applicable.
12 Heating
This clause of Part 1 is applicable.
13 Resistance to heat and fire
This clause of Part 1 is applicable.
14 Moisture resistance
This clause of Part 1 is applicable.
15 Resistance to rusting
This clause of Part 1 is applicable.
16 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable.

– 10 – IEC 62841-3-4:2016 © IEC 2016
17 Endurance
This clause of Part 1 is applicable.
18 Abnormal operation
This clause of Part 1 is applicable, except as follows:
18.5 Addition:
For bench grinders operated by three phase motors, the tests of 18.5.1 and 18.5.2 may be
replaced by the test of 18.5.3.
18.5.3 Addition:
If the test of 18.5.3 is applied, the tool shall be tested for a period of 5 min.
18.8 Electronic circuits providing safety critical functions
Replacement of Table 4 by the following:
Table 4 – Required performance levels
Type and purpose of SCF Minimum Performance Level
(PL)
For tools intended to be used with grinding wheels or wire brushes, power a
switch – prevent unwanted switch-on
For tools intended to be used with grinding wheels or wire brushes, power a
switch – provide desired switch-off
For tools not intended to be used with grinding wheels or wire brushes, Not an SCF
power switch – prevent unwanted switch-on
For tools not intended to be used with grinding wheels or wire brushes, Not an SCF
power switch – provide desired switch-off
Any electronic control to pass the test of 18.3 a
For tools intended to be used with grinding wheels, over-speed prevention to c
prevent output speed above 120 % of rated no-load speed
For tools not intended to be used with grinding wheels, over-speed a
prevention to prevent output speed above 130 % of rated no-load speed
Provide desired direction of rotation b
Prevent exceeding thermal limits as in Clause 18 a
Prevent self-resetting as required in 23.3 a

19 Mechanical hazards
This clause of Part 1 is applicable, except as follows:
19.1 Replacement of the first paragraph:
Moving and dangerous parts other than the accessories shall be so positioned or enclosed to
provide adequate protection against personal injury. The guarding of accessories is covered
in 19.1.101 through 19.1.103.
For grinding wheels and wire brushes, a guard in accordance with 19.1.101 and 19.1.102, a
work rest in accordance with 19.102 and a transparent screen in accordance with 19.1.103
shall be provided.
For polishing wheels, a guard, a work rest and a transparent screen are not required.
Guards for accessories shall not be removable without the aid of a tool.
19.1.101 Guards
The guard shall cover the periphery and the sides of the accessory, flanges and the end of
the tool spindle, except a portion of the accessory as allowed in 19.1.102 and indicated in
Figure 102.
The guard shall be designed so that the tool spindle cannot be fitted with an accessory
greater than 1,07 times the maximum diameter marked on the tool.
The guard shall be constructed so that removal of the peripheral protecting member is not
necessary for replacement of the accessory.
Compliance is checked by inspection and by measurement.
19.1.102 Openings in the guard
For grinding wheels and for wire brushes, the opening angle in the guard shall not exceed
65° above the horizontal plane passing through the centre of the wheel. The total opening
angle shall not exceed 90°. See Figure 102.
Compliance is checked by inspection and by measurement.
19.1.103 Transparent screens
Transparent screens shall be adjustable and have the minimum dimensions as specified in
Figure 103.
The operation of adjusting the screen shall not modify the adjustment of other parts of the
bench grinder.
The screen shall be made of transparent material having an appropriate resistance against
shattering, such as polycarbonate or laminated glass which is held in place by an interlayer,
between its two or more layers of glass.
For all bench grinders, the screens shall be mounted in such a way that the symmetrical axis
of the screen coincides with the vertical median plane of the working part of the grinding
wheel or the wire brush.
Compliance is checked by inspection.
19.6 Replacement:
The tool shall be designed so as to prevent excessive speed under normal use. The no-load
speed of the tool spindle at rated voltage shall not exceed the rated no-load speed.
Compliance is checked by measuring the speed of the tool spindle after the tool has been
operating for 5 min at no-load.

– 12 – IEC 62841-3-4:2016 © IEC 2016
19.7 Addition:
If a working stand is provided with a bench grinder, or is specifically identified in accordance
with 8.14.2, the requirements of 19.7 are also applicable to the combination of the bench
grinder and the working stand.
19.7.101 Bench grinders shall be provided with means to facilitate the fixing of the tool to a
bench, e.g. by providing holes in the base of the tool.
Compliance is checked by inspection.
19.8 This subclause is applicable for bench grinders, if provided with:
– wheels; or
– a pedestal with wheels.
19.101 Spark arrestor
For grinding wheels, a spark arrestor to limit the ejection of sparks and pieces of wheel from
the wheel guard shall be provided.
The spark arrestor shall be situated at the upper part of the wheel guard in line with the
periphery of the wheel and cover all the width of the wheel guard.
The spark arrestor shall be adjustable to within 2 mm of the surface of the wheel for all wheel
diameters between the maximum wheel diameter and 90 % of the smallest wheel diameter in
accordance with 8.3, see dimension E in Figure 102.
Compliance is checked by inspection and by measurement.
19.102 Work rest
The work rest shall not extend around the side of the wheel and cover at least the width of
the wheel guard. The work rest shall only be radially adjustable to within 2 mm of the
peripheral surface of the wheel for all wheel diameters between the maximum wheel diameter
and 90 % of the smallest wheel diameter in accordance with 8.3, see dimension F in
Figure 102.
The plane of the work rest surface shall either be fixed or be capable of adjustment only so
as to form an angle of not less than 85° to the tangent of the wheel with the smallest diameter
wheel in accordance with 8.3. See Figure 104.
If the work rest is adjustable in height, it shall be possible to achieve this angle at any height
setting.
Any required adjustment of the work rest shall be capable of being performed without the aid
of a tool.
Compliance is checked by inspection, by measurement and by manual test in accordance with
8.14.2 b).
19.103 Flanges
Bench grinders shall be provided with flanges for mounting grinding wheels to the tool
spindle. Flanges shall comply with the minimum dimensions in relation to the maximum
diameter D of the wheel, as specified in Table 101.

Table 101 – Minimum flange dimensions (see Figure 105)
Maximum wheel diameter d r T
f
mm mm mm
D ≤ 100 mm 34 6 1,5
42 8 1,5
100 mm < D ≤ 125 mm
125 mm < D ≤ 150 mm 52 9 1,5
150 mm < D ≤ 200 mm 68 12 1,5
85 15 1,5
200 mm < D ≤ 250 mm
100 17 1,5
250 mm < D ≤ 310 mm
Compliance is checked by measurement.
19.104 Torque test for flanges
The flanges required by 19.103 shall be designed so that they are of adequate strength.
Compliance is checked by the following test.
The abrasive wheel is replaced by a flat steel plate of sufficient thickness to be clamped
between the flanges, having the same bore diameter of the wheel and which extends beyond
the flanges.
The clamping nut shall be tightened with a first test torque according to Table 102. A feeler
gauge of thickness 0,05 mm shall be used to check whether the flanges are in contact with
the plate all around the circumference. It shall not be possible to push the feeler gauge
between the flange and the surface of the plate by more than 1 mm at any point around the
circumference of the flange, excluding any chamfer.
The test is then repeated using the second test torque according to Table 102.
Table 102 − Test torque for flanges
Thread First test torque Second test torque
Metric UNC Nm Nm
8 2 8
10 3/8 4 15
12 ½ 7,5 30
14 11 45
16 5/8 17,5 70
20 ¾ 35 140
> 20 > ¾ 75 300
19.105 Direction of accessory rotation
The periphery of all accessories shall move in a downward direction with respect to the
operator’s position.
Compliance is checked by inspection.
19.106 Eccentricity of the tool spindle and flange
The eccentricity of the tool spindle shall be less than 0,1 mm.

– 14 – IEC 62841-3-4:2016 © IEC 2016
For tools that provide for mounting of the accessory through the flange or similar clamping
and locating device, the total eccentricity of the combination of the tool spindle, the diameter
of the flange bore and the diameter of the part of the flange which locates and guides the
accessory shall be less than 0,3 mm.
Compliance is checked by measurement.
The eccentricity of the flange in the worst off-centre position allowed by the mounting
procedure is measured.
19.107 Out of balance
A bench grinder intended for use with grinding wheels of 100 mm or more in diameter shall
have adequate strength when out of balance.
Compliance is checked by the following test.
A simulated grinding wheel having a diameter equal to the maximum diameter marked on the
tool spindle in accordance with 8.3 is mounted on the tool spindle. The bench grinder is
then to be operated at no-load for 250 000 revolutions. The simulated wheel may consist of a
circular steel plate. The simulated wheel is to be out of balance, by the addition or removal of
material:
– for wheels less than 150 mm in diameter, by d /1 607 Nmm, where d is the diameter of the
wheel in mm;
– for wheels of 150 mm or more in diameter, by 14 Nmm.
After the test, the tool shall withstand the electric strength test of Annex D between live parts
and accessible parts and live parts shall not have become accessible as specified in
Clause 9. In addition, all guards shall remain intact.
20 Mechanical strength
This clause of Part 1 is applicable except as follows:
20.5 This subclause of Part 1 is not applicable.
20.101 Strength of guards
Guards for grinding wheels and wire brushes shall be made of a material with a minimum
peripheral thickness P and a minimum side thickness J as specified in Table 103 or Table 104
and illustrated in Figure 102.

Table 103 − Guard thickness for steel
Minimum Peripheral Maximum Maximum wheel diameter
ultimate speed wheel
D ≤ 125 mm 125 mm < D 200 mm < D 250 mm < D
tensile thickness
≤ 200 mm ≤ 250 mm ≤ 310 mm
strength
2 P J P J P J P J
N/mm m/s mm
mm mm mm mm mm mm mm mm
25 1,5 1,5 2 1,5 2,0 2 2,5 2,5
≥ 10 and
≤ 32
55 1,5 1,5 2 1,5 3 2 3,5 2,5
25 1,5 1,5 2 1,5 2,5 2 3,0 2,5
> 32 and
≤ 40
55 1,5 1,5 2 1,5 3,5 2 4,0 2,5
25 1,5 1,5 2 1,5 3 2 3,5 2,5
> 40 and
≤ 50
55 2 1,5 3 2 4,5 3 5,0 3,5
Table 104 − Guard thickness for aluminium
Minimum Peripheral Maximum Maximum wheel diameter
ultimate speed wheel
D ≤ 125 mm 125 mm < D 200 mm < D
tensile thickness
≤ 200 mm ≤ 250 mm
strength
P J P J P J
N/mm m/s mm
mm mm mm mm mm mm
10 5,5 5 6,5 5 8 6
≥ 10 and
20 6 5 8 6 10 8
≤ 32
200 32 6,5 5 9 7 12 10
10 6 5 8,5 7 10,5 9
> 32 and
≤ 50
20 7 6 10 8 13 11
10 2,5 2,5 3,5 3,5 4 4
≥ 10 and
20 3 3 4 4 5 5
≤ 40
32 3,5 3,5 4,5 4,5 6 5
10 3 3 4 4 5 5
> 40 and
20 3,5 3,5 4,5 4,5 6 5
≤ 50
32 4 4 5 5 7 6
Compliance is checked by inspection, by measurement and by either receipt of confirmation
of the ultimate tensile strength of the material from the material manufacturer or through
measurement of samples of the material.
20.102 Tool spindle
Tool spindles shall be made of steel and have sufficient size to support accessories with a
maximum diameter in accordance with 8.3. The diameter of the tool spindle shall comply with
the minimum values specified in Table 105.

– 16 – IEC 62841-3-4:2016 © IEC 2016
Table 105 – Minimum tool spindle diameter
Maximum accessory diameter Minimum tool spindle diameter
mm
D ≤ 80 mm
80 mm < D ≤ 155 mm
155 mm < D ≤ 206 mm 15
206 mm < D ≤ 256 mm
256 mm < D ≤ 310 mm 24
Compliance is checked by measurement.
20.103 Means for transportation
Means for transportation of bench grinders as required by 19.4 and as described in the
instructions in accordance with 8.14.2 b) 109) shall be of adequate strength to safely
transport the tool.
Compliance is checked by inspection and the following test.
Carrying means other than grasping surfaces on motor housings are subjected to a force
corresponding to three times the weight of the equipment but not more than 600 N per
carrying means. The force is applied in the direction of lifting uniformly over a 70 mm width at
the centre of the carrying means. The force is steadily increased so that the test value is
attained within 10 s and maintained for a period of 1 min.
If more than one carrying means is provided, the force is distributed between the carrying
means in the same proportion as in the normal transportation position. If the equipment is
provided with more than one carrying means, but so designed that it may readily be carried by
only one carrying means, each carrying means shall be capable of sustaining the total force.
The carrying means shall not break loose from the equipment and there shall not be any
permanent distortion, cracking or other evidence of failure.
20.104 Working stand
A working stand for a bench grinder, if provided with the tool or if specifically identified in
accordance with 8.14.2, shall have adequate strength.
Compliance is checked by the following test.
The bench grinder is mounted to the working stand and an additional vertical force of 3 times
the largest D is gradually applied for 1 min, distributed equally on the housing of the bench
grinder. During the test the working stand shall not collapse, and after removing the force it
shall not show any permanent deformation.
NOTE One example of achieving equal distribution of the additional force is using bags of sand or other similar
means.
21 Construction
This clause of Part 1 is applicable except as follows:
21.15 This subclause of Part 1 is not applicable.

21.18.2.1 Addition:
Bench grinders are not considered to give rise to danger on restoration of the voltage
supply.
21.30 This subclause of Part 1 is not applicable.
21.35 This subclause of Part 1 is not applicable.
21.101 Dust outlet
Connection ports for external dust collection equipment, if any, shall be directed away from
the operator.
Compliance is checked by inspection.
22 Internal wiring
This clause of Part 1 is applicable.
23 Components
This clause of Part 1 is applicable except as follows:
23.3 Addition:
For bench grinders, protection devices (e.g. overload or over-temperature protection
devices) or circuits that switch off the tool shall be of the non-self-resetting type.
24 Supply connection and external flexible cables and cords
This clause of Part 1 is applicable.
25 Terminals for external conductors
This clause of Part 1 is applicable.
26 Provision for earthing
This clause of Part 1 is applicable.
27 Screws and connections
This clause of Part 1 is applicable.
28 Creepage distances, clearances and distances through insulation
This clause of Part 1 is applicable.

– 18 – IEC 62841-3-4:2016 © IEC 2016
IEC
Key
1 grinding wheel 5 transparent screen
2 polishing wheel 6 spark arrestor
3 guard for grinding wheel or wire brush 7 power switch
4 work rest 8 dust outlet, if any
Figure 101 – Bench grinder
X E
≤65°
P
F
4 P J J
X
X - X
≤65°
≤90°
E
IEC
NOTE The lower part of Figure 102 is based on Figure 38.1 in the Standard for Stationary and Fixed Electric
Tools, UL 987, Edition 8.
Key
1 grinding wheel P thickness of the periphery of the guard
2 guard for grinding wheel or wire brush J thickness of the sides of the guard
3 work rest E clearance between spark arrestor and wheel
4 workpiece F clearance between work rest and wheel
5 transparent screen
6 guard for the tool spindle
7 spark arrestor
NOTE For articulation of the work rest, see Figure 104.
Figure 102 – Opening angles and dimensions for a guard

– 20 – IEC 62841-3-4:2016 © IEC 2016
b
B
IEC
Key
H ≥ 60 mm
b ≥ 75 mm
B ≥ 75 mm
1 median vertical plane of the working part of the wheel
Figure 103 – Transparent screen

≥ 85°
IEC
Key
1 adjustable work rest
Figure 104 – Bench grinder with inclinable work rest
H
r
T
d
f
IEC
Key
d external diameter of flange
f
r width of contact surface
T depth of recess
Figure 105 – Flange dimensions

– 22 – IEC 62841-3-4:2016 © IEC 2016
Annexes
The annexes of Part 1 are applicable except as follows.

Annex I
(informative)
Measurement of noise and vibration emissions

NOTE In Europe (EN 62841-3-4), Annex I is normative.
I.2 Noise test code (grade 2)
This clause of Part 1 is applicable except as follows:
I.2.4 Installation and mounting conditions of the power tools during noise tests
Addition:
Bench grinders supplied with a working stand are placed on this working stand standing on a
reflecting plane.
Othe
...

IEC 62841-3-4 ®
Edition 1.1 2019-07
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electric motor-operated hand-held tools, transportable tools and lawn and
garden machinery – Safety –
Part 3-4: Particular requirements for transportable bench grinders

Outils électroportatifs à moteur, outils portables et machines pour jardins
et pelouses – Sécurité –
Partie 3-4: Exigences particulières pour les tourets à meuler transportables

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IEC 62841-3-4 ®
Edition 1.1 2019-07
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electric motor-operated hand-held tools, transportable tools and lawn and

garden machinery – Safety –
Part 3-4: Particular requirements for transportable bench grinders

Outils électroportatifs à moteur, outils portables et machines pour jardins

et pelouses – Sécurité –
Partie 3-4: Exigences particulières pour les tourets à meuler transportables

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.140.20 ISBN 978-2-8322-7132-2

IEC 62841-3-4 ®
Edition 1.1 2019-07
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Electric motor-operated hand-held tools, transportable tools and lawn and
garden machinery – Safety –
Part 3-4: Particular requirements for transportable bench grinders

Outils électroportatifs à moteur, outils portables et machines pour jardins
et pelouses – Sécurité –
Partie 3-4: Exigences particulières pour les tourets à meuler transportables

– 2 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General requirements . 7
5 General conditions for the tests . 7
6 Radiation, toxicity and similar hazards . 7
7 Classification . 7
8 Marking and instructions . 7
9 Protection against access to live parts . 9
10 Starting . 9
11 Input and current . 9
12 Heating . 9
13 Resistance to heat and fire . 9
14 Moisture resistance . 9
15 Resistance to rusting . 9
16 Overload protection of transformers and associated circuits . 9
17 Endurance . 10
18 Abnormal operation . 10
19 Mechanical hazards . 10
20 Mechanical strength . 14
21 Construction . 16
22 Internal wiring . 17
23 Components . 17
24 Supply connection and external flexible cables and cords . 17
25 Terminals for external conductors . 17
26 Provision for earthing . 17
27 Screws and connections . 17
28 Creepage distances, clearances and distances through insulation . 17
Annexes . 22
Annex I (informative) Measurement of noise and vibration emissions . 22
Bibliography . 23

Figure 101 – Bench grinder . 18
Figure 102 – Opening angles and dimensions for a guard . 19
Figure 103 – Transparent screen . 20
Figure 104 – Bench grinder with inclinable work rest . 20
Figure 105 – Flange dimensions . 21
Figure 106 – Type 1 grinding wheel . 21

Table 4 – Required performance levels . 10

© IEC 2019
Table 101 – Minimum flange dimensions (see Figure 105) . 13
Table 102 − Test torque for flanges . 13
Table 103 − Guard thickness for steel . 15
Table 104 − Guard thickness for aluminium . 15
Table 105 – Minimum tool spindle diameter . 16
Table I.101 – Operating conditions for bench grinders . 22

– 4 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRIC MOTOR-OPERATED HAND-HELD TOOLS, TRANSPORTABLE
TOOLS AND LAWN AND GARDEN MACHINERY –
SAFETY –
Part 3-4: Particular requirements for transportable bench grinders
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 62841-3-4 edition 1.1 contains the first edition (2016-02) [documents 116/258/FDIS
and 116/275/RVD], its corrigendum (2016-12) and its amendment 1 (2019-07) [documents
116/381/CDV and 116/401/RVC].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
© IEC 2019
International Standard IEC 62841-3-4 has been prepared by IEC technical committee 116:
Safety of motor-operated electric tools.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This Part 3-4 is to be used in conjunction with the first edition of IEC 62841-1:2014.
This Part 3-4 supplements or modifies the corresponding clauses in IEC 62841-1, so as to
convert it into the IEC Standard: Particular requirements for transportable bench grinders.
Where a particular subclause of Part 1 is not mentioned in this Part 3-4, that subclause
applies as far as relevant. Where this standard states “addition”, “modification” or
“replacement”, the relevant text in Part 1 is to be adapted accordingly.
The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
The terms defined in Clause 3 are printed in bold typeface.
Subclauses, notes and figures which are additional to those in Part 1 are numbered starting
from 101.
A list of all parts of the IEC 62841 series, under the general title: Electric motor-operated
hand-held tools, transportable tools and lawn and garden machinery – Safety, can be found
on the IEC website.
The committee has decided that the contents of the base publication and its amendment will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 36 months from the date of publication.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
ELECTRIC MOTOR-OPERATED HAND-HELD TOOLS, TRANSPORTABLE
TOOLS AND LAWN AND GARDEN MACHINERY –
SAFETY –
Part 3-4: Particular requirements for transportable bench grinders

1 Scope
This clause of Part 1 is applicable, except as follows:
Addition:
This part of IEC 62841 applies to transportable bench grinders that can be equipped with
one or two accessories as follows:
– type 1 grinding wheels in accordance with ISO 603-4:1999 (see Figure 106) with a
diameter not exceeding 310 mm and a thickness not exceeding 55 mm;
– wire brushes with a diameter not exceeding 310 mm and a thickness not exceeding
55 mm;
– polishing wheels with a diameter not exceeding 310 mm;
and with a peripheral speed of any accessory between 10 m/s and 50 m/s.
NOTE Polishing wheels are also known as buffing wheels.
2 Normative references
This clause of Part 1 is applicable, except as follows:.
Addition:
ISO 603-4:1999, Bonded abrasive products – Dimensions – Part 4: Grinding wheels for
surface grinding/peripheral grinding
3 Terms and definitions
This clause of Part 1 is applicable, except as follows:
3.101
bench grinder
tool designed to grind, clean, polish or debur metal or similar materials by means of one or
two rotating accessories fixed to one or two tool spindles, see Figure 101, where the
workpiece is held by hand and possibly assisted by a work rest
3.102
tool spindle
drive spindle of a bench grinder which supports the accessories and provides the rotation
3.103
work rest
surface or device intended to support or to guide the workpiece

© IEC 2019
4 General requirements
This clause of Part 1 is applicable, except as follows:
4.101 D is understood to be the maximum diameter of the accessory to be used on each
tool spindle. Unless otherwise specified, tool spindle specific requirements dependent on D
shall be based on the value of D for the relevant tool spindle.
Throughout the remaining part of this document, unless otherwise explicitly stated, whenever
a requirement or a reference is made to “force” as multiple of D, the force shall be expressed
in newtons (N) and D shall be expressed in millimetres (mm).
5 General conditions for the tests
This clause of Part 1 is applicable, except as follows:
5.17 Addition:
The mass of the tool shall include the guards, work rests and transparent screens. Any
additional parts such as leg sets or carrying means that are required in accordance with the
instructions for the safe use of the tool shall be included in the mass.
6 Radiation, toxicity and similar hazards
This clause of Part 1 is applicable.
7 Classification
This clause of Part 1 is applicable.
8 Marking and instructions
This clause of Part 1 is applicable except as follows:
8.1 Addition:
Tools shall be marked with:
– rated no-load speed of the tool spindle(s).
8.2 Addition:
Tools shall be marked with the following safety warnings:
– “ WARNING Always wear eye protection” or the symbol M004 of ISO 7010 or the
following safety sign:
– a warning near any polishing spindle (i.e. a spindle without a guard) never to use a
grinding wheel or wire brush on the polishing side of the tool, if applicable.

– 8 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
8.3 Addition:
Bench grinders shall be marked with the minimum and maximum diameter of the accessory
to be used on each tool spindle.
Bench grinders shall be marked with the direction of rotation of the tool spindle, indicated in
a visible location on the tool in the vicinity of the tool spindle, by an arrow raised or recessed
or by any other means no less visible and indelible.
8.14.1 Addition:
The additional safety instructions as specified in 8.14.1.101 shall be given. This part may be
printed separately from the “General power tool safety warnings”.
8.14.1.101 Safety instructions for bench grinders
Bench grinder safety warnings
a) Do not use a damaged accessory. Before each use, inspect the accessory such as
abrasive wheels for chips and cracks and wire brushes for loose or cracked wires.
After inspecting and installing an accessory, position yourself and bystanders away
from the plane of the rotating accessory and run the power tool at maximum no-load
speed for one minute. Damaged accessories will normally break apart during this test
time.
NOTE 1 For tools that are not intended for wire brushes, the phrase “and wire brushes for loose or cracked
wires” is omitted.
b) The rated speed of the accessory must be at least equal to the maximum speed
marked on the power tool. Accessories running faster than their rated speed can break
and fly apart.
c) Be aware that wire bristles are thrown by the wire brush even during ordinary
operation. Do not overstress the wires by applying excessive load to the wire brush.
The wire bristles can easily penetrate light clothing and/or skin.
NOTE 2 The above safety warning applies only to tools intended to be used with wire brushes.
d) Never grind on the sides of a grinding wheel. Grinding on the side can cause the wheel
to break and fly apart.
8.14.2 a) Addition:
101) Information about details and type of the accessory(ies) recommended for each tool
spindle, e.g. the maximum thickness of the accessory and the diameter of the hole in
the accessory;
102) Instruction to use only accessories with a diameter according to the relevant marking
as required by 8.3;
103) Instruction to ensure that the bench grinder is always stable and secure (e.g. fixed to
a bench) and instruction how to fix the tool to a workbench or the like;
104) Instructions on the correct mounting of wheels and ensuring that wheels are free of
defects before use, including instructions for performing a ring test for cracks.
8.14.2 b) Addition:
101) Instruction to adjust the spark arrestor and the work rest frequently so as to
compensate for wear of the wheel;
102) Instruction to keep the distance between the spark arrestor/work rest and the wheel
as small as possible and in any case not greater than 2 mm;
103) Instruction to replace the worn wheel when these gaps are no longer able to be
maintained;
© IEC 2019
104) For tools with two spindles: instruction to always use the tool with accessories on both
spindles in order to limit the risk of contact with the rotating spindle;
105) Instruction to always use the guard, work rest, transparent screen and spark arrestor
as required for the accessory(ies);
106) For tools with a vertically adjustable or inclinable work rest: instruction on how to
properly adjust and secure the work rest angle in relation to the wheel;
107) Instructions on how to perform grinding functions safely;
108) Instruction to replace damaged or deeply grooved wheels;
109) Instruction where to lift and support the bench grinder during transportation;
110) Instruction to always adjust the work rest so that the angle between the work rest and
the tangent of the accessory is always greater than 85°.
8.14.2 c) Addition:
101) Instructions for handling and storage of grinding wheels and wire brushes, if
applicable.
9 Protection against access to live parts
This clause of Part 1 is applicable.
10 Starting
This clause of Part 1 is applicable.
11 Input and current
This clause of Part 1 is applicable.
12 Heating
This clause of Part 1 is applicable.
13 Resistance to heat and fire
This clause of Part 1 is applicable.
14 Moisture resistance
This clause of Part 1 is applicable.
15 Resistance to rusting
This clause of Part 1 is applicable.
16 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable.

– 10 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
17 Endurance
This clause of Part 1 is applicable.
18 Abnormal operation
This clause of Part 1 is applicable, except as follows:
18.5 Addition:
For bench grinders operated by three phase motors, the tests of 18.5.1 and 18.5.2 may be
replaced by the test of 18.5.3.
18.5.3 Addition:
If the test of 18.5.3 is applied, the tool shall be tested for a period of 5 min.
18.8 Electronic circuits providing safety critical functions
Replacement of Table 4 by the following:
Table 4 – Required performance levels
Type and purpose of SCF Minimum Performance Level
(PL)
For tools intended to be used with grinding wheels or wire brushes, power a
switch – prevent unwanted switch-on
For tools intended to be used with grinding wheels or wire brushes, power a
switch – provide desired switch-off
For tools not intended to be used with grinding wheels or wire brushes, Not an SCF
power switch – prevent unwanted switch-on
For tools not intended to be used with grinding wheels or wire brushes, Not an SCF
power switch – provide desired switch-off
Any electronic control to pass the test of 18.3 a
For tools intended to be used with grinding wheels, over-speed prevention to c
prevent output speed above 120 % of rated no-load speed
For tools not intended to be used with grinding wheels, over-speed a
prevention to prevent output speed above 130 % of rated no-load speed
Provide desired direction of rotation b
Prevent exceeding thermal limits as in Clause 18 a
Prevent self-resetting as required in 23.3 a

19 Mechanical hazards
This clause of Part 1 is applicable, except as follows:
19.1 Replacement of the first paragraph:
Moving and dangerous parts other than the accessories shall be so positioned or enclosed to
provide adequate protection against personal injury. The guarding of accessories is covered
in 19.1.101 through 19.1.103.
© IEC 2019
For grinding wheels and wire brushes, a guard in accordance with 19.1.101 and 19.1.102, a
work rest in accordance with 19.102 and a transparent screen in accordance with 19.1.103
shall be provided.
For polishing wheels, a guard, a work rest and a transparent screen are not required.
Guards for accessories shall not be removable without the aid of a tool.
19.1.101 Guards
The guard shall cover the periphery and the sides of the accessory, flanges and the end of
the tool spindle, except a portion of the accessory as allowed in 19.1.102 and indicated in
Figure 102.
The guard shall be designed so that the tool spindle cannot be fitted with an accessory
greater than 1,07 times the maximum diameter marked on the tool.
The guard shall be constructed so that removal of the peripheral protecting member is not
necessary for replacement of the accessory.
Compliance is checked by inspection and by measurement.
19.1.102 Openings in the guard
For grinding wheels and for wire brushes, the opening angle in the guard shall not exceed
65° above the horizontal plane passing through the centre of the wheel. The total opening
angle shall not exceed 90°. See Figure 102.
Compliance is checked by inspection and by measurement.
19.1.103 Transparent screens
Transparent screens shall be adjustable and have the minimum dimensions as specified in
Figure 103.
The operation of adjusting the screen shall not modify the adjustment of other parts of the
bench grinder.
The screen shall be made of transparent material having an appropriate resistance against
shattering, such as polycarbonate or laminated glass which is held in place by an interlayer,
between its two or more layers of glass.
For all bench grinders, the screens shall be mounted in such a way that the symmetrical axis
of the screen coincides with the vertical median plane of the working part of the grinding
wheel or the wire brush.
Compliance is checked by inspection.
19.6 Replacement:
The tool shall be designed so as to prevent excessive speed under normal use. The no-load
speed of the tool spindle at rated voltage shall not exceed the rated no-load speed.
Compliance is checked by measuring the speed of the tool spindle after the tool has been
operating for 5 min at no-load.

– 12 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
19.7 Addition:
If a working stand is provided with a bench grinder, or is specifically identified in accordance
with 8.14.2, the requirements of 19.7 are also applicable to the combination of the bench
grinder and the working stand.
19.7.101 Bench grinders shall be provided with means to facilitate the fixing of the tool to a
bench, e.g. by providing holes in the base of the tool.
Compliance is checked by inspection.
19.8 This subclause is applicable for bench grinders, if provided with:
– wheels; or
– a pedestal with wheels.
19.101 Spark arrestor
For grinding wheels, a spark arrestor to limit the ejection of sparks and pieces of wheel from
the wheel guard shall be provided.
The spark arrestor shall be situated at the upper part of the wheel guard in line with the
periphery of the wheel and cover all the width of the wheel guard.
The spark arrestor shall be adjustable to within 2 mm of the surface of the wheel for all wheel
diameters between the maximum wheel diameter and 90 % of the smallest wheel diameter in
accordance with 8.3, see dimension E in Figure 102.
Compliance is checked by inspection and by measurement.
19.102 Work rest
The work rest shall not extend around the side of the wheel and cover at least the width of
the wheel guard. The work rest shall only be radially adjustable to within 2 mm of the
peripheral surface of the wheel for all wheel diameters between the maximum wheel diameter
and 90 % of the smallest wheel diameter in accordance with 8.3, see dimension F in
Figure 102.
The plane of the work rest surface shall either be fixed or be capable of adjustment only so
as to form an angle of not less than 85° to the tangent of the wheel with the smallest diameter
wheel in accordance with 8.3. See Figure 104.
If the work rest is adjustable in height, it shall be possible to achieve this angle at any height
setting.
Any required adjustment of the work rest shall be capable of being performed without the aid
of a tool.
Compliance is checked by inspection, by measurement and by manual test in accordance with
8.14.2 b).
19.103 Flanges
Bench grinders shall be provided with flanges for mounting grinding wheels to the tool
spindle. Flanges shall comply with the minimum dimensions in relation to the maximum
diameter D of the wheel, as specified in Table 101.

© IEC 2019
Table 101 – Minimum flange dimensions (see Figure 105)
Maximum wheel diameter d r T
f
mm mm mm
34 6 1,5
D ≤ 100 mm
42 8 1,5
100 mm < D ≤ 125 mm
125 mm < D ≤ 150 mm 52 9 1,5
150 mm < D ≤ 200 mm 68 12 1,5
85 15 1,5
200 mm < D ≤ 250 mm
250 mm < D ≤ 310 mm 100 17 1,5

Compliance is checked by measurement.
19.104 Torque test for flanges
The flanges required by 19.103 shall be designed so that they are of adequate strength.
Compliance is checked by the following test.
The abrasive wheel is replaced by a flat steel plate of sufficient thickness to be clamped
between the flanges, having the same bore diameter of the wheel and which extends beyond
the flanges.
The clamping nut shall be tightened with a first test torque according to Table 102. A feeler
gauge of thickness 0,05 mm shall be used to check whether the flanges are in contact with
the plate all around the circumference. It shall not be possible to push the feeler gauge
between the flange and the surface of the plate by more than 1 mm at any point around the
circumference of the flange, excluding any chamfer.
The test is then repeated using the second test torque according to Table 102.
Table 102 − Test torque for flanges
Thread First test torque Second test torque
Metric UNC Nm Nm
8 2 8
10 3/8 4 15
12 ½ 7,5 30
14 11 45
16 5/8 17,5 70
20 ¾ 35 140
> 20 > ¾ 75 300
19.105 Direction of accessory rotation
The periphery of all accessories shall move in a downward direction with respect to the
operator’s position.
Compliance is checked by inspection.
19.106 Eccentricity of the tool spindle and flange
The eccentricity of the tool spindle shall be less than 0,1 mm.

– 14 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
For tools that provide for mounting of the accessory through the flange or similar clamping
and locating device, the total eccentricity of the combination of the tool spindle, the diameter
of the flange bore and the diameter of the part of the flange which locates and guides the
accessory shall be less than 0,3 mm.
Compliance is checked by measurement.
The eccentricity of the flange in the worst off-centre position allowed by the mounting
procedure is measured.
19.107 Out of balance
A bench grinder intended for use with grinding wheels of 100 mm or more in diameter shall
have adequate strength when out of balance.
Compliance is checked by the following test.
A simulated grinding wheel having a diameter equal to the maximum diameter marked on the
tool spindle in accordance with 8.3 is mounted on the tool spindle. The bench grinder is
then to be operated at no-load for 250 000 revolutions. The simulated wheel may consist of a
circular steel plate. The simulated wheel is to be out of balance, by the addition or removal of
material:
– for wheels less than 150 mm in diameter, by d /1 607 Nmm, where d is the diameter of the
wheel in mm;
– for wheels of 150 mm or more in diameter, by 14 Nmm.
After the test, the tool shall withstand the electric strength test of Annex D between live parts
and accessible parts and live parts shall not have become accessible as specified in
Clause 9. In addition, all guards shall remain intact.
20 Mechanical strength
This clause of Part 1 is applicable except as follows:
20.5 This subclause of Part 1 is not applicable.
20.101 Strength of guards
Guards for grinding wheels and wire brushes shall be made of a material with a minimum
peripheral thickness P and a minimum side thickness J as specified in Table 103 or Table 104
and illustrated in Figure 102.

© IEC 2019
Table 103 − Guard thickness for steel
Minimum Peripheral Maximum Maximum wheel diameter
ultimate speed wheel
D ≤ 125 mm 125 mm < D 200 mm < D 250 mm < D
tensile thickness
≤ 200 mm ≤ 250 mm ≤ 310 mm
strength
2 P J P J P J P J
N/mm m/s mm
mm mm mm mm mm mm mm mm
25 1,5 1,5 2 1,5 2,0 2 2,5 2,5
≥ 10 and
≤ 32
55 1,5 1,5 2 1,5 3 2 3,5 2,5
25 1,5 1,5 2 1,5 2,5 2 3,0 2,5
> 32 and
≤ 40
55 1,5 1,5 2 1,5 3,5 2 4,0 2,5
25 1,5 1,5 2 1,5 3 2 3,5 2,5
> 40 and
≤ 50
55 2 1,5 3 2 4,5 3 5,0 3,5
Table 104 − Guard thickness for aluminium
Minimum Peripheral Maximum Maximum wheel diameter
ultimate wheel
speed
D ≤ 125 mm 125 mm < D 200 mm < D
tensile thickness
≤ 200 mm ≤ 250 mm
strength
2 P J P J P J
N/mm m/s mm
mm mm mm mm mm mm
10 5,5 5 6,5 5 8 6
≥ 10 and
20 6 5 8 6 10 8
≤ 32
200 32 6,5 5 9 7 12 10
10 6 5 8,5 7 10,5 9
> 32 and
≤ 50
20 7 6 10 8 13 11
10 2,5 2,5 3,5 3,5 4 4
≥ 10 and
20 3 3 4 4 5 5
≤ 40
32 3,5 3,5 4,5 4,5 6 5
10 3 3 4 4 5 5
> 40 and
20 3,5 3,5 4,5 4,5 6 5
≤ 50
32 4 4 5 5 7 6
Compliance is checked by inspection, by measurement and by either receipt of confirmation
of the ultimate tensile strength of the material from the material manufacturer or through
measurement of samples of the material.
20.102 Tool spindle
Tool spindles shall be made of steel and have sufficient size to support accessories with a
maximum diameter in accordance with 8.3. The diameter of the tool spindle shall comply with
the minimum values specified in Table 105.

– 16 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
Table 105 – Minimum tool spindle diameter
Maximum accessory diameter Minimum tool spindle diameter
mm
D ≤ 80 mm 8
80 mm < D ≤ 155 mm
155 mm < D ≤ 206 mm 15
206 mm < D ≤ 256 mm
256 mm < D ≤ 310 mm 24
Compliance is checked by measurement.
20.103 Means for transportation
Means for transportation of bench grinders as required by 19.4 and as described in the
instructions in accordance with 8.14.2 b) 109) shall be of adequate strength to safely
transport the tool.
Compliance is checked by inspection and the following test.
Carrying means other than grasping surfaces on motor housings are subjected to a force
corresponding to three times the weight of the equipment but not more than 600 N per
carrying means. The force is applied in the direction of lifting uniformly over a 70 mm width at
the centre of the carrying means. The force is steadily increased so that the test value is
attained within 10 s and maintained for a period of 1 min.
If more than one carrying means is provided, the force is distributed between the carrying
means in the same proportion as in the normal transportation position. If the equipment is
provided with more than one carrying means, but so designed that it may readily be carried by
only one carrying means, each carrying means shall be capable of sustaining the total force.
The carrying means shall not break loose from the equipment and there shall not be any
permanent distortion, cracking or other evidence of failure.
20.104 Working stand
A working stand for a bench grinder, if provided with the tool or if specifically identified in
accordance with 8.14.2, shall have adequate strength.
Compliance is checked by the following test.
The bench grinder is mounted to the working stand and an additional vertical force of 3 times
the largest D is gradually applied for 1 min, distributed equally on the housing of the bench
grinder. During the test the working stand shall not collapse, and after removing the force it
shall not show any permanent deformation.
NOTE One example of achieving equal distribution of the additional force is using bags of sand or other similar
means.
21 Construction
This clause of Part 1 is applicable except as follows:
21.15 This subclause of Part 1 is not applicable.

© IEC 2019
21.18.2.1 Addition:
Bench grinders are not considered to give rise to danger on restoration of the voltage
supply.
21.30 This subclause of Part 1 is not applicable.
21.35 This subclause of Part 1 is not applicable.
21.101 Dust outlet
Connection ports for external dust collection equipment, if any, shall be directed away from
the operator.
Compliance is checked by inspection.
22 Internal wiring
This clause of Part 1 is applicable.
23 Components
This clause of Part 1 is applicable except as follows:
23.3 Addition:
For bench grinders, protection devices (e.g. overload or over-temperature protection
devices) or circuits that switch off the tool shall be of the non-self-resetting type.
24 Supply connection and external flexible cables and cords
This clause of Part 1 is applicable.
25 Terminals for external conductors
This clause of Part 1 is applicable.
26 Provision for earthing
This clause of Part 1 is applicable.
27 Screws and connections
This clause of Part 1 is applicable.
28 Creepage distances, clearances and distances through insulation
This clause of Part 1 is applicable.

– 18 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
6 2
IEC
Key
1 grinding wheel 5 transparent screen
2 polishing wheel 6 spark arrestor
3 guard for grinding wheel or wire brush 7 power switch
4 work rest 8 dust outlet, if any
Figure 101 – Bench grinder
© IEC 2019
X E
≤65°
1 P
F
4 P J J
X
X - X
≤65°
≤90°
E
IEC
NOTE The lower part of Figure 102 is based on Figure 38.1 in the Standard for Stationary and Fixed Electric
Tools, UL 987, Edition 8.
Key
1 grinding wheel P thickness of the periphery of the guard
2 guard for grinding wheel or wire brush J thickness of the sides of the guard
3 work rest E clearance between spark arrestor and wheel
4 workpiece F clearance between work rest and wheel
5 transparent screen
6 guard for the tool spindle
7 spark arrestor
NOTE For articulation of the work rest, see Figure 104.
Figure 102 – Opening angles and dimensions for a guard

– 20 – IEC 62841-3-4:2016+AMD1:2019 CSV
© IEC 2019
b
B
IEC
Key
H ≥ 60 mm
b ≥ 75 mm
B ≥ 75 mm
1 median vertical plane of the working part of the wheel
Figure 103 – Transparent screen

≥ 85°
IEC
Key
1 adjustable work rest
Figure 104 – Bench grinder with incl
...

IEC 62841-3-4 ®
Edition 1.2 2024-02
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electric motor-operated hand-held tools, transportable tools and lawn and
garden machinery – Safety –
Part 3-4: Particular requirements for transportable bench grinders

Outils électroportatifs à moteur, outils portables et machines pour jardins et
pelouses – Sécurité –
Partie 3-4: Exigences particulières pour les tourets à meuler transportables

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IEC 62841-3-4 ®
Edition 1.2 2024-02
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electric motor-operated hand-held tools, transportable tools and lawn and
garden machinery – Safety –
Part 3-4: Particular requirements for transportable bench grinders
Outils électroportatifs à moteur, outils portables et machines pour jardins et
pelouses – Sécurité –
Partie 3-4: Exigences particulières pour les tourets à meuler transportables
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.140.20 ISBN 978-2-8322-8376-9

IEC 62841-3-4 ®
Edition 1.2 2024-02
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Electric motor-operated hand-held tools, transportable tools and lawn and
garden machinery – Safety –
Part 3-4: Particular requirements for transportable bench grinders

Outils électroportatifs à moteur, outils portables et machines pour jardins et
pelouses – Sécurité –
Partie 3-4: Exigences particulières pour les tourets à meuler transportables

– 2 – IEC 62841-3-4:2016+AMD1:2019
+AMD2:2024 CSV © IEC 2024
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General requirements . 7
5 General conditions for the tests . 7
6 Radiation, toxicity and similar hazards . 7
7 Classification . 7
8 Marking and instructions . 7
9 Protection against access to live parts . 9
10 Starting . 9
11 Input and current . 9
12 Heating . 10
13 Resistance to heat and fire . 10
14 Moisture resistance . 10
15 Resistance to rusting . 10
16 Overload protection of transformers and associated circuits . 10
17 Endurance . 10
18 Abnormal operation . 10
19 Mechanical hazards . 11
20 Mechanical strength . 16
21 Construction . 18
22 Internal wiring . 18
23 Components . 18
24 Supply connection and external flexible cables and cords . 18
25 Terminals for external conductors . 18
26 Provision for earthing . 19
27 Screws and connections . 19
28 Creepage distances, clearances and distances through insulation . 19
Annexes . 24
Annex I (informative) Measurement of noise and vibration emissions . 24
Bibliography . 25

Figure 101 – Bench grinder . 19
Figure 102 – Opening angles and dimensions for a guard . 20
Figure 103 – Transparent screen . 21
Figure 104 – Bench grinder with inclinable work rest . 21
Figure 105 – Flange dimensions . 22
Figure 106 – Type 1 grinding wheel . 22
Figure 107 – Brush guard . 23

Table 4 – Required performance levels . 11

+AMD2:2024 CSV © IEC 2024
Table 101 – Minimum flange dimensions (see Figure 105) . 14
Table 102 − Test torque for flanges . 15
Table 103 − Guard thickness for steel . 16
Table 104 − Guard thickness for aluminium . 16
Table 105 – Minimum tool spindle diameter . 17
Table I.101 – Operating conditions for bench grinders . 24

– 4 – IEC 62841-3-4:2016+AMD1:2019
+AMD2:2024 CSV © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRIC MOTOR-OPERATED HAND-HELD TOOLS, TRANSPORTABLE
TOOLS AND LAWN AND GARDEN MACHINERY –
SAFETY –
Part 3-4: Particular requirements for transportable bench grinders

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 62841-3-4 edition 1.2 contains the first edition (2016-02) [documents 116/258/FDIS
and 116/275/RVD], its corrigendum (2016-12), its amendment 1 (2019-07) [documents
116/381/CDV and 116/401/RVC] and its amendment 1 (2024-02) [documents 116/693/FDIS
and 116/731/RVD].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendments 1 and 2. Additions are in green text, deletions are in
strikethrough red text. A separate Final version with all changes accepted is available
in this publication.
+AMD2:2024 CSV © IEC 2024
International Standard IEC 62841-3-4 has been prepared by IEC technical committee 116:
Safety of motor-operated electric tools.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This Part 3-4 is to be used in conjunction with the first edition of IEC 62841-1:2014.
This Part 3-4 supplements or modifies the corresponding clauses in IEC 62841-1, so as to
convert it into the IEC Standard: Particular requirements for transportable bench grinders.
Where a particular subclause of Part 1 is not mentioned in this Part 3-4, that subclause
applies as far as relevant. Where this standard states “addition”, “modification” or
“replacement”, the relevant text in Part 1 is to be adapted accordingly.
The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
The terms defined in Clause 3 are printed in bold typeface.
Subclauses, notes and figures which are additional to those in Part 1 are numbered starting
from 101.
A list of all parts of the IEC 62841 series, under the general title: Electric motor-operated
hand-held tools, transportable tools and lawn and garden machinery – Safety, can be found
on the IEC website.
The committee has decided that the contents of this document and its amendments will
remain unchanged until the stability date indicated on the IEC website under webstore.iec.ch
in the data related to the specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
NOTE The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 36 months from the date of publication.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – IEC 62841-3-4:2016+AMD1:2019
+AMD2:2024 CSV © IEC 2024
ELECTRIC MOTOR-OPERATED HAND-HELD TOOLS, TRANSPORTABLE
TOOLS AND LAWN AND GARDEN MACHINERY –
SAFETY –
Part 3-4: Particular requirements for transportable bench grinders

1 Scope
This clause of Part 1 is applicable, except as follows:
Addition:
This part of IEC 62841 applies to transportable bench grinders that can be equipped with
one or two accessories as follows:
– type 1 grinding wheels in accordance with ISO 603-4:1999 (see Figure 106) with a
diameter not exceeding 310 mm and a thickness not exceeding 55 mm;
– wire brushes with a diameter not exceeding 310 mm and a thickness not exceeding
55 mm;
– polishing wheels with a diameter not exceeding 310 mm;
and with a peripheral speed of any accessory between 10 m/s and 50 m/s.
NOTE Polishing wheels are also known as buffing wheels.
This document does not apply to tools intended for lapidary grinding operations.
2 Normative references
This clause of Part 1 is applicable, except as follows:.
Addition:
ISO 603-4:1999, Bonded abrasive products – Dimensions – Part 4: Grinding wheels for
surface grinding/peripheral grinding
3 Terms and definitions
This clause of Part 1 is applicable, except as follows:
3.101
bench grinder
tool designed to grind, clean, polish or debur metal or similar materials by means of one or
two rotating accessories fixed to one or two tool spindles, see Figure 101, where the
workpiece is held by hand and possibly assisted by a work rest
3.102
tool spindle
drive spindle of a bench grinder which supports the accessories and provides the rotation

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3.103
work rest
surface or device intended to support or to guide the workpiece
3.104
brush guard
guard which partly encloses the wire brush and gives protection to the operator
3.105
wheel guard
guard which partly encloses the type 1 grinding wheel and gives protection to the operator
4 General requirements
This clause of Part 1 is applicable, except as follows:
4.101 D is understood to be the maximum diameter of the accessory to be used on each
tool spindle. Unless otherwise specified, tool spindle specific requirements dependent on D
shall be based on the value of D for the relevant tool spindle.
Throughout the remaining part of this document, unless otherwise explicitly stated, whenever
a requirement or a reference is made to “force” as multiple of D, the force shall be expressed
in newtons (N) and D shall be expressed in millimetres (mm).
5 General conditions for the tests
This clause of Part 1 is applicable, except as follows:
5.17 Addition:
The mass of the tool shall include the guards, work rests and transparent screens. Any
additional parts such as leg sets or carrying means that are required in accordance with the
instructions for the safe use of the tool shall be included in the mass.
6 Radiation, toxicity and similar hazards
This clause of Part 1 is applicable.
7 Classification
This clause of Part 1 is applicable.
8 Marking and instructions
This clause of Part 1 is applicable except as follows:
8.1 Addition:
Tools shall be marked with:
– rated no-load speed of the tool spindle(s).

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8.2 Addition:
Tools shall be marked with the following safety warnings:
– “ WARNING Always wear eye protection” or the symbol M004 of ISO 7010 or the
following safety sign:
– a warning near any polishing spindle (i.e. a spindle without a guard) never to use a
grinding wheel or wire brush on the polishing side of the tool, if applicable.
8.3 Addition:
Bench grinders shall be marked with the minimum and maximum diameter of the accessory
to be used on each tool spindle.
Bench grinders shall be marked with the direction of rotation of the tool spindle, indicated in
a visible location on the tool in the vicinity of the tool spindle, by an arrow raised or recessed
or by any other means no less visible and indelible.
8.14.1 Addition:
The additional safety instructions as specified in 8.14.1.101 shall be given. This part may be
printed separately from the “General power tool safety warnings”.
8.14.1.101 Safety instructions for bench grinders
Bench grinder safety warnings
a) Do not use a damaged accessory. Before each use, inspect the accessory such as
abrasive wheels for chips and cracks and wire brushes for loose or cracked wires.
After inspecting and installing an accessory, position yourself and bystanders away
from the plane of the rotating accessory and run the power tool at maximum no-load
speed for one minute. Damaged accessories will normally break apart during this test
time.
NOTE 1 For tools that are not intended for wire brushes, the phrase “and wire brushes for loose or cracked
wires” is omitted.
b) The rated speed of the accessory must be at least equal to the maximum speed
marked on the power tool. Accessories running faster than their rated speed can break
and fly apart.
c) Be aware that wire bristles are thrown by the wire brush even during ordinary
operation. Do not overstress the wires by applying excessive load to the wire brush.
The wire bristles can easily penetrate light clothing and/or skin.
NOTE 2 The above safety warning applies only to tools intended to be used with wire brushes.
d) Never grind on the sides of a grinding wheel. Grinding on the side can cause the wheel
to break and fly apart.
e) Use only accessories that are specified for your power tool and the specific guard
designed for the selected accessory. Accessories for which the power tool was not
designed cannot be adequately guarded.

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8.14.2 a) Addition:
101) Information about details and type of the accessory(ies) recommended for each tool
spindle, e.g. the maximum thickness of the accessory and the diameter of the hole in
the accessory;
102) Instruction to use only accessories with a diameter according to the relevant marking
as required by 8.3;
103) Instruction to ensure that the bench grinder is always stable and secure (e.g. fixed to
a bench) and instruction how to fix the tool to a workbench or the like;
104) Instructions on the correct mounting of wheels and ensuring that wheels are free of
defects before use, including instructions for performing a ring test for cracks.
105) Information about the correct guard to be used for each recommended accessory.
8.14.2 b) Addition:
101) Instruction to adjust the spark arrestor and the work rest frequently so as to
compensate for wear of the wheel;
102) Instruction to keep the distance between the spark arrestor/work rest and the wheel
as small as possible and in any case not greater than 2 mm;
103) Instruction to replace the worn wheel when these gaps are no longer able to be
maintained;
104) For tools with two spindles: instruction to always use the tool with accessories on both
spindles in order to limit the risk of contact with the rotating spindle;
105) Instruction to always use the guard, work rest, transparent screen and spark arrestor
as required for the accessory(ies);
106) For tools with a vertically adjustable or inclinable work rest: instruction on how to
properly adjust and secure the work rest angle in relation to the wheel;
107) Instructions on how to perform grinding functions safely;
108) Instruction to replace damaged or deeply grooved wheels;
109) Instruction where to lift and support the bench grinder during transportation;
110) Instruction to always adjust the work rest so that the angle between the work rest and
the tangent of the accessory is always greater than 85°.
8.14.2 c) Addition:
101) Instructions for handling and storage of grinding wheels and wire brushes, if
applicable.
9 Protection against access to live parts
This clause of Part 1 is applicable.
10 Starting
This clause of Part 1 is applicable.
11 Input and current
This clause of Part 1 is applicable.

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12 Heating
This clause of Part 1 is applicable.
13 Resistance to heat and fire
This clause of Part 1 is applicable.
14 Moisture resistance
This clause of Part 1 is applicable.
15 Resistance to rusting
This clause of Part 1 is applicable.
16 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable.
17 Endurance
This clause of Part 1 is applicable.
18 Abnormal operation
This clause of Part 1 is applicable, except as follows:
18.5 Addition:
For bench grinders operated by three phase motors, the tests of 18.5.1 and 18.5.2 may be
replaced by the test of 18.5.3.
18.5.3 Addition:
If the test of 18.5.3 is applied, the tool shall be tested for a period of 5 min.
18.8 Electronic circuits providing safety critical functions
Replacement of Table 4 by the following:

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Table 4 – Required performance levels
Type and purpose of SCF Minimum Performance Level
(PL)
For tools intended to be used with grinding wheels or wire brushes, power a
switch – prevent unwanted switch-on
For tools intended to be used with grinding wheels or wire brushes, power a
switch – provide desired switch-off
For tools not intended to be used with grinding wheels or wire brushes, Not an SCF
power switch – prevent unwanted switch-on
For tools not intended to be used with grinding wheels or wire brushes, Not an SCF
power switch – provide desired switch-off
Any electronic control to pass the test of 18.3 a
For tools intended to be used with grinding wheels, over-speed prevention to c
prevent output speed above 120 % of rated no-load speed
For tools not intended to be used with grinding wheels, over-speed a
prevention to prevent output speed above 130 % of rated no-load speed
Provide desired direction of rotation b
Prevent exceeding thermal limits as in Clause 18 a
Prevent self-resetting as required in 23.3 a

19 Mechanical hazards
This clause of Part 1 is applicable, except as follows:
19.1 Replacement of the first paragraph:
Moving and dangerous parts other than the accessories shall be so positioned or enclosed to
provide adequate protection against personal injury. The guarding of accessories is covered
in 19.1.101 through 19.1.103.
For grinding wheels and wire brushes, a guard in accordance with 19.1.101 and 19.1.102, a
work rest in accordance with 19.102 and a transparent screen in accordance with 19.1.103
shall be provided.
For polishing wheels, a guard, a work rest and a transparent screen are not required.
Guards for accessories shall not be removable without the aid of a tool.
19.1.101 Guards
The guard shall cover the periphery and the sides of the accessory, flanges and the end of
the tool spindle, except a portion of the accessory as allowed in 19.1.102 and indicated in
Figure 102.
The guard shall be designed so that the tool spindle cannot be fitted with an accessory
greater than 1,07 times the maximum diameter marked on the tool.
The guard shall be constructed so that removal of the peripheral protecting member is not
necessary for replacement of the accessory.
Compliance is checked by inspection and by measurement.

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19.1.102 Openings in the guard
For grinding wheels and for wire brushes, the opening angle in the guard shall not exceed
65° above the horizontal plane passing through the centre of the wheel. The total opening
angle shall not exceed 90°. See Figure 102.
Compliance is checked by inspection and by measurement.
19.1.103 Transparent screens
Transparent screens shall be adjustable and have the minimum dimensions as specified in
Figure 103.
The operation of adjusting the screen shall not modify the adjustment of other parts of the
bench grinder.
The screen shall be made of transparent material having an appropriate resistance against
shattering, such as polycarbonate or laminated glass which is held in place by an interlayer,
between its two or more layers of glass.
For all bench grinders, the screens shall be mounted in such a way that the symmetrical axis
of the screen coincides with the vertical median plane of the working part of the grinding
wheel or the wire brush.
Compliance is checked by inspection.
19.1 Replacement of the first paragraph:
Moving and dangerous parts other than the accessories shall be so positioned or enclosed to
provide adequate protection against personal injury. The guarding of accessories is covered
in 19.1.101 through 19.1.104.
For grinding wheels, a wheel guard in accordance with 19.1.101 and 19.1.102, a work rest in
accordance with 19.102 and a transparent screen in accordance with 19.1.103 shall be
provided.
For wire brushes, a brush guard in accordance with 19.1.104 and a transparent screen in
accordance with 19.1.103 shall be provided. For brush guards where the angle α as shown in
Figure 107 is < 90°, a work rest in accordance with 19.102 is required.
For polishing wheels, a guard, a work rest and a transparent screen are not required.
Wheel guards and brush guards
– shall be designed so that the tool spindle cannot be fitted with an accessory greater than
1,07 times the maximum diameter marked on the bench grinder; and
– shall not be removable without the aid of a tool.
19.1.101 Guards
Replace the existing title and text with the following:
19.1.101 Wheel guards
Wheel guards shall cover the periphery and the sides of the accessory, flanges and the end
of the tool spindle, except a portion of the accessory as allowed in 19.1.102 and indicated in
Figure 102.
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The wheel guard shall be constructed so that removal of the peripheral protecting member is
not necessary for replacement of the accessory.
Compliance is checked by inspection and by measurement.
19.1.102 Openings in the guard
Replace the existing title and text with the following:
19.1.102 Openings in the wheel guard
The opening angle in a wheel guard shall not exceed 65° above the horizontal plane passing
through the centre of the wheel. The total opening angle shall not exceed 90°. See
Figure 102.
Compliance is checked by inspection and by measurement.
19.1.104 Brush guards
Brush guards shall cover an area of ≥ 180° of the periphery of the wire brush. The opening
angle shall not exceed 65° above the horizontal plane passing through the centre of the wire
brush. The width of the brush guard shall at least cover the length of the tool spindle. The
brush guard may be open laterally, see Figure 107.
Compliance is checked by inspection and measurement.
19.6 Replacement:
The tool shall be designed so as to prevent excessive speed under normal use. The no-load
speed of the tool spindle at rated voltage shall not exceed the rated no-load speed.
Compliance is checked by measuring the speed of the tool spindle after the tool has been
operating for 5 min at no-load.
19.7 Addition:
If a working stand is provided with a bench grinder, or is specifically identified in accordance
with 8.14.2, the requirements of 19.7 are also applicable to the combination of the bench
grinder and the working stand.
19.7.101 Bench grinders shall be provided with means to facilitate the fixing of the tool to a
bench, e.g. by providing holes in the base of the tool.
Compliance is checked by inspection.
19.8 This subclause is applicable for bench grinders, if provided with:
– wheels; or
– a pedestal with wheels.
19.101 Spark arrestor
For grinding wheels, a spark arrestor to limit the ejection of sparks and pieces of wheel from
the wheel guard shall be provided.
The spark arrestor shall be situated at the upper part of the wheel guard in line with the
periphery of the wheel and cover all the width of the wheel guard.

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The spark arrestor shall be adjustable to within 2 mm of the surface of the wheel for all wheel
diameters between the maximum wheel diameter and 90 % of the smallest wheel diameter in
accordance with 8.3, see dimension E in Figure 102.
Compliance is checked by inspection and by measurement.
19.102 Work rest
The work rest shall not extend around the side of the wheel and cover at least the width of
the wheel guard. The work rest shall only be radially adjustable to within 2 mm of the
peripheral surface of the wheel for all wheel diameters between the maximum wheel diameter
and 90 % of the smallest wheel diameter in accordance with 8.3, see dimension F in
Figure 102.
The plane of the work rest surface shall either be fixed or be capable of adjustment only so
as to form an angle of not less than 85° to the tangent of the wheel with the smallest diameter
wheel in accordance with 8.3. See Figure 104.
If the work rest is adjustable in height, it shall be possible to achieve this angle at any height
setting.
Any required adjustment of the work rest shall be capable of being performed without the aid
of a tool.
Compliance is checked by inspection, by measurement and by manual test in accordance with
8.14.2 b).
19.103 Flanges
Bench grinders shall be provided with flanges for mounting grinding wheels to the tool
spindle. Flanges shall comply with the minimum dimensions in relation to the maximum
diameter D of the wheel, as specified in Table 101.
Table 101 – Minimum flange dimensions (see Figure 105)
Maximum wheel diameter d r T
f
mm mm mm
D ≤ 100 mm 34 6 1,5
100 mm < D ≤ 125 mm 42 8 1,5
52 9 1,5
125 mm < D ≤ 150 mm
68 12 1,5
150 mm < D ≤ 200 mm
200 mm < D ≤ 250 mm 85 15 1,5
250 mm < D ≤ 310 mm 100 17 1,5

Compliance is checked by measurement.
19.104 Torque test for flanges
The flanges required by 19.103 shall be designed so that they are of adequate strength.
Compliance is checked by the following test.
The abrasive wheel is replaced by a flat steel plate of sufficient thickness to be clamped
between the flanges, having the same bore diameter of the wheel and which extends beyond
the flanges.
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The clamping nut shall be tightened with a first test torque according to Table 102. A feeler
gauge of thickness 0,05 mm shall be used to check whether the flanges are in contact with
the plate all around the circumference. It shall not be possible to push the feeler gauge
between the flange and the surface of the plate by more than 1 mm at any point around the
circumference of the flange, excluding any chamfer.
The test is then repeated using the second test torque according to Table 102.
Table 102 − Test torque for flanges
Thread First test torque Second test torque
Metric UNC Nm Nm
8 2 8
10 3/8 4 15
12 ½ 7,5 30
14 11 45
16 5/8 17,5 70
20 ¾ 35 140
> 20 > ¾ 75 300
19.105 Direction of accessory rotation
The periphery of all accessories shall move in a downward direction with respect to the
operator’s position.
Compliance is checked by inspection.
19.106 Eccentricity of the tool spindle and flange
The eccentricity of the tool spindle shall be less than 0,1 mm.
For tools that provide for mounting of the accessory through the flange or similar clamping
and locating device, the total eccentricity of the combination of the tool spindle, the diameter
of the flange bore and the diameter of the part of the flange which locates and guides the
accessory shall be less than 0,3 mm.
Compliance is checked by measurement.
The eccentricity of the flange in the worst off-centre position allowed by the mounting
procedure is measured.
19.107 Out of balance
A bench grinder intended for use with grinding wheels of 100 mm or more in diameter shall
have adequate strength when out of balance.
Compliance is checked by the following test.
A simulated grinding wheel having a diameter equal to the maximum diameter marked on the
tool spindle in accordance with 8.3 is mounted on the tool spindle. The bench grinder is
then to be operated at no-load for 250 000 revolutions. The simulated wheel may consist of a
circular steel plate. The simulated wheel is to be out of balance, by the addition or removal of
material:
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– for wheels less than 150 mm in diameter, by d /1 607 Nmm, where d is the diameter of the
wheel in mm;
– for wheels of 150 mm or more in diameter, by 14 Nmm.
After the test, the tool shall withstand the electric strength test of Annex D between live parts
and accessible parts and live parts shall not have become accessible as specified in
Clause 9. In addition, all guards shall remain intact.
20 Mechanical strength
This clause of Part 1 is applicable except as follows:
20.5 This subclause of Part 1 is not applicable.
20.101 Strength of guards
Guards for grinding wheels and wire brushes shall be made of a material with a minimum
peripheral thickness P and a minimum side thickness J as specified in Table 103 or Table 104
and illustrated in Figure 102.
Table 103 − Guard thickness for steel
Minimum Peripheral Maximum Maximum wheel diameter
ultimate speed wheel
D ≤ 125 mm 125 mm < D 200 mm < D 250 mm < D
tensile thickness
≤ 200 mm ≤ 250 mm ≤ 310 mm
strength
P J P J P J P J
N/mm m/s mm
mm mm mm mm mm mm mm mm
25 1,5 1,5 2 1,5 2,0 2 2,5 2,5
≥ 10 and
≤ 32
55 1,5 1,5 2 1,5 3 2 3,5 2,5
25 1,5 1,5 2 1,5 2,5 2 3,0 2,5
> 32 and
≤ 40
55 1,5 1,5 2 1,5 3,5 2 4,0 2,5
25 1,5 1,5 2 1,5 3 2 3,5 2,5
> 40 and
≤ 50
55 2 1,5 3 2 4,5 3 5,0 3,5
Table 104 − Guard thickness for aluminium
Minimum Peripheral Maximum Maximum wheel diameter
ultimate speed wheel
D ≤ 125 mm 125 mm < D 200 mm < D
tensile thickness
≤ 200 mm ≤ 250 mm
strength
P J P J P J
N/mm m/s mm
mm mm mm mm mm mm
10 5,5 5 6,5 5 8 6
≥ 10 and
20 6 5 8 6 10 8
≤ 32
200 32 6,5 5 9 7 12 10
10 6 5 8,5 7 10,5 9
> 32 and
≤ 50
20 7 6 10 8 13 11
310 10 2,5 2,5 3,5 3,5 4 4
≥ 10 and
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20 3 3 4 4 5 5
32 3,5 3,5 4,5 4,5 6 5
10 3 3 4 4 5 5
> 40 and
20 3,5 3,5 4,5 4,5 6 5
≤ 50
32 4 4 5 5 7 6
Compliance is checked by inspection, by measurement and by either receipt of confirmation
of the ultimate tensile strength of the material from the material manufacturer or through
measurement of samples of the material.
20.102 Tool spindle
Tool spindles shall be made of steel and have sufficient size to support accessories with a
maximum diameter in accordance with 8.3. The diameter of the tool spindle shall comply with
the minimum values specified in Table 105.
Table 105 – Minimum tool spindle diameter
Maximum accessory diameter Minimum tool spindle diameter
mm
D ≤ 80 mm
80 mm < D ≤ 155 mm 12
155 mm < D ≤ 206 mm
206 mm < D ≤ 256 mm 18
256 mm < D ≤ 310 mm
Compliance is checked by measurement.
20.103 Means for transportation
Means for transportation of bench grinders as required by 19.4 and as described in the
instructions in accordance with 8.14.2 b) 109) shall be of adequate strength to safely
transport the tool.
Compliance is checked by inspection and the following test.
Carrying means other than grasping surfaces on motor housings are subjected to a force
corresponding to three times the weight of the equipment but not more than 600 N per
carrying means. The force is applied in the direction of lifting uniformly over a 70 mm width at
the centre of the carrying means. The force is steadily increased so that the test value is
attained within 10 s and maintained for a period of 1 min.
If more than one carrying means is provided, the force is distributed between the carrying
means in the same proportion as in the normal transportation position. If the equipment is
provided with more than one carrying means, but so designed that it may readily be carried by
only one carrying means, each carrying means shall be capable of sustaining the total force.
The carrying means shall not break loose from the equipment and there shall not be any
permanent distortion, cracking or other evidence of failure.
20.104 Working stand
A working stand for a bench grinder, if provided with the tool or if specifically identified in
accordance with 8.14.2, shall have adequate strength.

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