EN 13236:2019

SLOVENSKI STANDARD
01-oktober-2019
Nadomešča:
SIST EN 13236:2011+A1:2016
Varnostne zahteve za superabrazive
Safety requirements for superabrasive products
Sicherheitsanforderungen für Schleifwerkzeuge mit Diamant oder Bornitrid
Prescriptions de sécurité pour les produits superabrasifs
Ta slovenski standard je istoveten z: EN 13236:2019
ICS:
25.100.70 Brusiva Abrasives
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13236
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2019
EUROPÄISCHE NORM
ICS 25.100.70 Supersedes EN 13236:2010+A1:2015
English Version
Safety requirements for superabrasive products
Prescriptions de sécurité pour les produits Sicherheitsanforderungen für Schleifwerkzeuge mit
superabrasifs Diamant oder Bornitrid
This European Standard was approved by CEN on 26 November 2018.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13236:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and symbols . 6
3.1 General . 6
3.2 Grinding and cutting-off machines . 7
3.3 Grinding and cutting-off methods . 7
3.4 Type of application . 8
3.5 Symbols . 9
4 List of significant hazards . 11
5 Safety requirements . 11
5.1 General requirements . 11
5.2 Requirements for precision superabrasive grinding and cutting-off wheels . 12
5.2.1 Bore tolerances . 12
5.2.2 Sequence of maximum operating speeds . 12
5.2.3 Safety factors. 12
5.2.4 Maximum operating speeds . 12
5.2.5 Blotters . 13
5.3 Requirements for non-precision cutting-off wheels . 13
5.3.1 Bore tolerances . 13
5.3.2 Sequence of maximum operating speeds . 13
5.3.3 Safety factors. 14
5.3.4 Maximum operating speeds . 14
5.3.5 Requirements for the blank . 15
5.3.6 Requirements for the connection of the superabrasive section to the blank . 19
5.3.7 Tensioning of non-precision cutting-off wheels . 21
5.3.8 Limitation of side coating of abrasive grain and/or superabrasive grain . 21
5.4 Requirements for diamond wires . 21
5.4.1 General . 21
5.4.2 Requirements . 22
5.4.3 Maximum operating speeds . 22
5.5 Requirements for mounted points . 22
5.5.1 Spindle diameter tolerances . 22
5.5.2 Sequence of maximum operating speeds . 22
5.5.3 Safety factors. 23
5.6 Requirements for other superabrasive products for non-precision grinding . 23
5.6.1 Bore diameter tolerances . 23
5.6.2 Sequence of maximum operating speeds . 23
5.6.3 Safety factors. 23
5.6.4 Maximum operating speeds . 23
5.6.5 Requirements for the connection of the abrasive section to the core . 24
5.7 Marking . 24
6 Verification of the safety requirements . 24
6.1 Verification of the general requirements . 24
6.1.1 General . 24
6.1.2 Visual inspection . 25
6.1.3 Ring test . 25
6.2 Verification of the strength requirements . 25
6.2.1 Verification of the safety factor . 25
6.2.2 Verification of the bending moment of non-precision cutting-off wheels . 25
6.2.3 Verification of the strength requirements for other superabrasive products for non-
precision grinding . 29
6.2.4 Verification methods for diamond wires . 30
6.3 Verification of marking . 33
6.4 Verification of the requirements for blotters . 33
6.5 Verification of the tensioning of non-precision cutting-off wheels . 33
7 Information for use . 35
Annex A (normative) Marking . 36
A.1 Content of the marking . 36
A.1.1 Marking requirements . 36
A.1.2 Additional inscriptions . 39
A.1.2.1 General . 39
A.1.2.2 Multiple or gang mounted wheels . 39
A.2 Execution of marking . 39
Annex B (informative) Mounted points . 41
B.1 Example of calculation of the maximum permissible speed of rotation . 41
B.2 Example for the application of the calculation method . 45
B.2.1 Types of mounted points . 45
B.2.2 Assumptions for the calculation . 46
B.2.3 Maximum permissible speeds of rotation . 47
Annex C (normative) Reconditioning of cutting-off wheels according to 5.3.6.4 . 49
C.1 Preconditions for reconditioning . 49
C.2 Additional marking requirements . 49
Annex D (informative) Speed conversion table . 50
Bibliography . 53

European foreword
This document (EN 13236:2019) has been prepared by Technical Committee CEN/TC 143 “Machine
tools — Safety”, the secretariat of which is held by SNV.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2019, and conflicting national standards shall
be withdrawn at the latest by October 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 13236:2010+A1:2015.
Significant changes between EN 13236:2010+A1:2015 and EN 13236:2019 are as follows:
a) added the hazard “kickback” in Table 4;
b) added vacuum brazed products in Table 6 for maximum operating speeds;
c) added mobile cutting-off machines in Table 10;
d) revised the definitions and requirements for openings to achieve a better distinction and to avoid
different interpretations;
e) merged the tables for bending strength and bending moment for cutting-off wheels for the use on
hand-held cutting-off machines into one table and updated the values for minimum requirements
for destructive testing.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
This European Standard has been prepared to provide one means of conforming with essential safety
requirements, e.g. of the General Product Safety Directive and associated EFTA regulations.
This European Standard is addressed to designers, manufacturers and suppliers of the superabrasive
products described in the scope as well as to those who are reconditioning superabrasive cutting-off
wheels. In addition, it helps designers, manufacturers and suppliers of grinding machines in the
selection of superabrasive products, in order to reduce the risks and achieve conformity of the
respective machinery with the essential health and safety requirements of the Machinery Directive.
The extent to which hazards are covered is indicated in the scope of this European Standard.
1 Scope
This document applies to superabrasives products containing natural or synthetic diamond or cBN
(cubic boron nitride). It includes precision grinding and cutting-off wheels, non-precision cutting-off
wheels, diamond wires, mounted points and other superabrasive products for non-precision grinding. It
also applies to reconditioned superabrasive cutting-off wheels.
This document specifies requirements and/or measures for the removal or reduction of hazards
resulting from the design and application of the superabrasive products.
This document contains also procedures and tests for verification of the compliance with the
requirements as well as safety information for use, which will be made available to the user by the
manufacturer.
This document does not apply to bonded abrasive products, coated abrasive products, rotating dressing
tools, truers or any non-rotating superabrasive products.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 286-2:2010, Geometrical product specifications (GPS) - ISO code system for tolerances on linear
sizes - Part 2: Tables of standard tolerance classes and limit deviations for holes and shafts (ISO 286-
2:2010)
ISO 22917, Precision superabrasives — Limit deviations and run-out tolerances for grinding wheels with
diamond or cubic boron nitride
3 Terms, definitions and symbols
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 General
3.1.1
superabrasive product
abrasive product containing natural or synthetic diamond or cubic boron nitride in a bond
3.2 Grinding and cutting-off machines
3.2.1
stationary machine
machine being fixed in position during operation
Note 1 to entry: See, for example, EN ISO 16089.
Note 2 to entry: Included are fixed swing frame machines and mobile machines clamped firmly in position
during use.
Note 3 to entry: Transportable machines are fixed in position during operation and therefore considered to be
stationary machines.
3.2.2
stationary machine with totally enclosed working area
stationary machine being protected by separating guards in such a way that machining processes
including loading and unloading of workpieces are carried out inside them and persons are protected
against hazards generated by bursting of an abrasive product
3.2.3
mobile machine
machine not being fixed in position during operation
Note 1 to entry: Mobile machines are manually guided (but not hand-held) by the operator during use, e.g. floor
grinding machines.
3.2.4
hand-held machine
machine being held in the hand during operation
Note 1 to entry: Included are machines with flexible drives.
Note 2 to entry: See for example EN ISO 11148-7, EN ISO 11148-9, EN 60745-2-3 and EN ISO 19432.
3.3 Grinding and cutting-off methods
3.3.1
peripheral grinding
grinding with the periphery of the wheel with no or limited side loads
3.3.2
face grinding
grinding with the face of the wheel
3.3.3
cutting-off
cutting-off or slotting with the periphery of the cutting-off wheel
3.4 Type of application
3.4.1
mechanically guided grinding and cutting-off
process with feed movements of the abrasive product and/or workpiece guided by mechanical means
Note 1 to entry: See Table 1.
3.4.2
manually guided grinding and cutting-off
process with feed movements of the abrasive product and/or the workpiece manually guided by the
operator
Note 1 to entry: See Table 1.
3.4.3
hand-held grinding and cutting-off
process with the machine entirely guided by the operator
Note 1 to entry: See Table 1.
Table 1 — Type of application
Super-
Grinding Type of Type of Examples for
abrasive Workpiece
method machine application application/machines
product
Surface grinding, centerless
mechanically grinding, creep feed grinding,
fixed
guided bevel grinding on glass (glass
bevelling machine)
mechanically Profile grinding of stone and
stationary mechanically fixed
guided concrete
grinding guided
machines grinding Internal grinding, external,
plunge and traverse grinding, jig
mechanically mechanically grinding, decorative stone
guided guided milling and polishing, pencil
edging of glass (automotive
grinding
glass)
Roughing and polishing of stone
manually
fixed floors (carriage/floor grinding
stationary
guided
manually
machine)
and mobile
guided
grinding
Tool grinding (bench grinding
grinding
manually
machines
fixed machine), decorative glass
guided
grinding
hand-held Stone and concrete milling and
hand-held manually
grinding fixed polishing (angle/straight
grinding guided
machines grinder)
mechanically Cutting-off of bricks and tiles
fixed
guided (table saw)
stationary mechanically Cutting-off of stone and concrete
mechanically
cutting-off guided fixed (bridge-type saw, floor and wall
guided
machines cutting-off saw, wire saw)
mechanically mechanically
Cutting-off of semi-conductors
guided guided
cutting-
off
manually Cutting-off of stone and concrete
stationary
fixed
manually
guided (table saw, floor saw)
and mobile
guided
cutting-off
manually
cutting-off
fixed Cutting-off of bricks (table saw)
machines
guided
hand-held Cutting-off of stone and concrete
hand-held manually
cutting-off fixed (angle grinder, hand-held
cutting-off guided
machines cutting-off machine)
3.5 Symbols
For the purposes of this document, the symbols listed in Table 2 and Table 3 apply.
Table 2 — Symbols
Symbol Designation Definition Unit
Bursting speed divided by maximum
operating speed:
f
burst speed factor —
br
v
br
f =
br
v
s
Revolutions per minute at which the
deflection speed of
n
spindle of mounted points is deflecting 1/min
ab
mounted points
under centrifugal force
Revolutions per minute of a new
maximum permissible
n
abrasive product at maximum 1/min
max
speed of rotation
operating speed
Deflection speed divided by maximum
permissible speed of rotation:
safety factor against
S
spindle deflection for —
ab
n
ab
mounted points
S =
ab
n
max
Bursting speed divided by maximum
operating speed, all squared:
safety factor against
S
bursting due to centrifugal —
br

v
br
force
S = 
br

v
s
Maximum permissible peripheral
v
maximum operating speed m/s
s
speed of a rotating abrasive product
Peripheral speed at which an abrasive
v
bursting speed product breaks due to centrifugal m/s
br
force
Peripheral speed which an abrasive
v
minimum bursting speed product shall at least reach without m/s
br,min
bursting due to centrifugal force

Table 3 — Other symbols
Symbol Designation Unit
F force N
F
shearing force N
A
L
lever arm mm
F
M
bending moment Nm
b
σ
bending strength N/mm
b
τ
shear strength N/mm
S
4 List of significant hazards
The significant hazards are listed in Table 4.
Table 4 — List of significant hazards
Hazard designation Hazardous situations Relevant clauses in this standard
(Examples)
Ejection of parts 1. Abrasive product breakage —
caused by:
— improper design 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7,
Annex B and Annex C
— manufacturing defects 5.1
— wrong selection Clause 7, Annex A
— improper handling and storage Clause 7
— improper use (mounting and Clause 7
grinding process)
2. Grinding debris Clause 7
Vibration Hand arm vibration on hand- —
held machines caused by:
— improper use Clause 7
— incorrect mounting Clause 7
Kickback Kickback effect of cutting-off —
wheels on hand-held
machines caused by:
— improper use Clause 7
— wobbling of cutting-off wheels 5.3.7
due to wrong tensioning
— side coating of cutting-off 5.3.8
wheels
5 Safety requirements
5.1 General requirements
Superabrasive products shall be designed and manufactured in such a way that they resist the forces
and loads that are to be expected when used as intended. They shall not present visible defects affecting
safety and shall comply with the requirements listed in the following clauses.
5.2 Requirements for precision superabrasive grinding and cutting-off wheels
5.2.1 Bore tolerances
The tolerance class for bores on precision superabrasive grinding and cutting-off wheels is given in
ISO 22917.
5.2.2 Sequence of maximum operating speeds
Precision superabrasive grinding and cutting-off wheels shall be manufactured for maximum operating
speeds according to the following sequence:
< 16 — 20 — 25 — 32 — 35 — 40 — 45 — 50 — 63 — 80 — 100 — 125 — 140 — 160 — 180 — 200
— 225 — 250 — 280 — 320 in m/s.
Intermediate maximum operating speeds should only be used where the application requirements
demand it.
NOTE For conversion of peripheral speeds into speeds of rotation for different outside diameters D of the
abrasive product, see Annex D.
5.2.3 Safety factors
Precision superabrasive grinding and cutting-off wheels shall have a safety factor against bursting due
to centrifugal forces at their maximum operating speed as given in Table 5.
Table 5 — Safety factors for precision superabrasive grinding and cutting-off wheels
Maximum
Type of machine Type of application Safety factor Burst speed factor
operating speed
v S f
s br br
m/s
mechanically
guided grinding ≤ 80 3,0 1,73
and cutting-off
mechanically
stationary
guided grinding
machines
and cutting-off
≤ 320 1,75 1,32
with totally
enclosed working
area
manually guided ≤ 63 3,0 1,73
stationary and
grinding and
mobile machines
80 3,5 1,87
cutting-off
5.2.4 Maximum operating speeds
Precision superabrasive grinding and cutting-off wheels shall comply with the classification of the
sequence of maximum operating speeds in 5.2.2 up to the maximum values given in Table 6.
In the totally enclosed working area, the maximum operating speeds given in Table 6 may be exceeded,
if the safety factor required in Table 5 is complied with.
Table 6 — Maximum operating speeds as a function of the bond type
Maximum operating speed
v
s
m/s
Core Abrasive section
Single layer:
electroplated
Vitrified Resinoid Metal
and vacuum
V B M brazed
G
Manufactured on core, e.g.
— 100 100 200
sintered or electroplated
Metal
Connected to core, e.g.
180 80 100 —
cemented, screwed,
clamped, brazed or welded
Manufactured on core, e.g.
— 100 — —
pressed
Resinoid
Connected to core, e.g.
80 80 80 80
cemented, screwed, clamped
Manufactured on core, e.g.
80 — — —
pressed
Vitrified
Connected to core, e.g.
80 80 80 —
cemented, screwed, clamped
5.2.5 Blotters
Blotters shall be supplied by the manufacturer, supplier or importer where these are required for a safe
mounting and use of the superabrasive product.
Blotters shall be made of suitable compressible material. Shape, dimensions and material shall be
adapted to application and intended use. When water-based coolants are used the blotter material shall
not be affected in the way that it loses its compressibility and physical function.
Blotters can serve as a label for the marking provided the marking requirements of this standard are
met and the blotter is firmly attached to the wheel.
5.3 Requirements for non-precision cutting-off wheels
5.3.1 Bore tolerances
The tolerance class for bores for non-precision cutting-off wheels is H9 as per EN ISO 286-2:2010.
5.3.2 Sequence of maximum operating speeds
Non-precision cutting-off wheels shall be manufactured for maximum operating speeds conforming to
the following sequence:
20 — 25 — 32 — 35 — 40 — 45 — 50 — 63 — 80 — 100 in m/s.
Intermediate maximum operating speeds should only be used where the application requirements
demand it.
NOTE For conversion of peripheral speeds into speeds of rotation for different outside diameters D of the
abrasive product, see Annex D.
5.3.3 Safety factors
Non-precision cutting-off wheels shall have a safety factor against bursting due to centrifugal forces at
their maximum operating speed as given in Table 7.
Table 7 — Safety factors for non-precision cutting-off wheels
Maximum Safety factor Burst speed factor
operating speed
Type of machine Type of application
v S f
s br br
m/s
mechanically guided
≤ 100 2,0 1,41
cutting-off
stationary
mechanically guided
cutting-off
cutting-off with
machines
≤ 100 1,75 1,32
totally enclosed
working area
stationary and
manually guided
mobile cutting-off ≤ 100 3,5 1,87
cutting-off
machines
hand-held
hand-held
cutting-off ≤ 100 3,5 1,87
cutting-off
machines
5.3.4 Maximum operating speeds
Non-precision cutting-off wheels shall comply with the sequence of maximum operating speeds in 5.3.2
up to the maximum values given in Table 8.
Table 8 — Maximum operating speeds as a function of the bond type
Maximum operating speed
v
s
m/s
Cutting rim
Single layer:
(abrasive Type of application
electroplated
section)
Metal
and vacuum
M
brazed
G
mechanically and manually
continuous 100 100
guided cutting-off
mechanically and manually
segmented 100 100
guided cutting-off
continuous or
hand-held cutting-off 100 100
segmented
5.3.5 Requirements for the blank
5.3.5.1 Requirements for the blank of cutting-off wheels for dry cutting-off
5.3.5.1.1 Dimensions
Dimensions of blanks of non-precision cutting-off wheels for dry cutting-off, see Table 9.
Table 9 — Dimensions of blanks for dry cutting-off
Outside diameter of the blank Blank thickness
D E
Type of machine 1
mm mm
D ≤ 115 ≥ 0,7
Hand-held cutting-off
115 < D ≤ 200 ≥ 0,9
machines
200 < D ≤ 230 ≥ 1,2
Hand-held and 230 < D ≤ 300 ≥ 1,2
stationary cutting-off
300 < D ≤ 400
≥ 1,6
machines 1
350 < D ≤ 400 ≥ 1,6
400 < D ≤ 500 ≥ 2,0
Stationary and mobile
500 < D ≤ 600 ≥ 2,5
cutting-off machines
600 < D ≤ 900 ≥ 3,0
900 < D ≤ 1 600 ≥ 3,5
5.3.5.1.2 Material and hardness of blanks for laser welded cutting-off wheels
The material used for the blank shall be steel which shall have the necessary properties enabling it to
produce adequate joint strength when welding it to the segments. For example, alloyed cold worked
steels having a maximum carbon content of 0,27 % are suitable.
Blanks shall have a minimum hardness of 20 HRC for outside diameter D ≤ 230 mm and a minimum
hardness of 24 HRC for outside diameter D > 230 mm.
5.3.5.1.3 Material and hardness of blanks for sintered and direct melted cutting-off wheels
The material used for the blank shall be tool steel.
5.3.5.1.4 Surface finish of the entire slot area
Cutting-off wheels shall be manufactured in such a way that the surface finish in the area of the slots
does not cause crack formation.
5.3.5.1.5 Other requirements
Blanks shall be free from visible defects.
5.3.5.2 Requirements for the blank of cutting-off wheels for wet cutting-off
5.3.5.2.1 Dimensions
Dimensions of blanks for non-precision cutting-off wheels for wet cutting-off, see Table 10.
Table 10 — Dimensions of blanks for wet cutting-off
Outside diameter of the blank Blank thickness
D E
Type of machine
mm mm
D ≤ 300 ≥ 1,2
300 < D ≤ 400 ≥ 1,6
400 < D ≤ 500 ≥ 2,0
500 < D ≤ 600 ≥ 2,5
stationary and mobile
cutting-off machines
600 < D ≤ 900 ≥ 2,8
900 < D ≤ 2 500 ≥ 3,5
2 500 < D ≤ 3 500 ≥ 7,0
3 500 < D ≤ 5 000 ≥ 9,0
D ≤ 230 ≥ 0,006 D
1 1
hand-held cutting-off
machines
230 < D ≤ 400 ≥ 0,005 D
1 1
5.3.5.2.2 Material
The material used for the blank shall be tool steel.
5.3.5.2.3 Surface finish of the entire slot area
See 5.3.5.1.4.
5.3.5.2.4 Other requirements
See 5.3.5.1.5.
5.3.5.3 Design and position of openings in the blank of cutting-off wheels for hand-held
applications
5.3.5.3.1 General
A distinction is made between different types of openings in the blank regarding crack propagation. The
different types are:
1) Cuts: A cut is an opening with a width of less than 0,8 mm;
2) Circular and elliptical openings with a ratio of large to small radius ≤ (2:1);
3) “Other openings”: All openings other than types 1) and 2).
Circular and elliptical openings minimize crack propagation whereas “other openings” and cuts might
support it due to a higher notch effect (stress concentration). Therefore, circular and elliptical openings
are treated in a different way compared to “other openings” and cuts.
Openings in blanks of cutting-off wheels for hand-held applications designed for any reasons such as
noise dampening shall comply with the following limitations:
a) The total area of openings in blanks excluding the bore shall be ≤ 20 % of the area of the blank;
b) Openings outside the flange area shall end at a distance x ≥ 0,25 D/2 outside of the diameter of the
bore, where D is the outside diameter of the cut-off wheel. See also Figure 1;
c) Openings outside the flange area other than circular and elliptical openings shall end at a distance
of ≥ 15 % of the blank radius D /2 away from the closest slot or outside diameter of the blank. See
also Figure 1;
d) Inside the flange area no openings other than drive pin holes or holes for fixing of functional
elements are allowed. No more than 2 drive pin holes and 8 fixing holes are allowed. Maximum hole
diameter for fixing holes is 8 mm. See also Figure 1.
Peripheral slots with or without holes at their ends and the bore shall not be considered as openings
according to this subclause.
Key
restricted area, see limitations b) and c) above

D outside diameter
D outside diameter of the blank
Figure 1 — Position of openings in blanks
5.3.5.3.2 Dimensions and distribution of cuts
a) Cuts outside the flange area shall have a dimension in radial direction of ≤ 40 % of the blank radius
D /2.
b) The minimum distance between cuts outside the flange area at any point of the cut shall be ≥ 15 %
of the radius D/2 of the cutting-off wheel.
c) Cuts shall start and end with a spiral.
5.3.5.3.3 Dimensions and distribution of “other openings”
“Other openings” in blanks shall have a dimension in radial direction of ≤ 15 % of the radius D/2 of the
cutting-off wheel with an opening angle of 15° at maximum, see Figure 2 as an example.
Key
1 flange area
Figure 2 — Example of “other openings”
5.3.5.4 Heat treatment of all blanks
If slots or openings are produced by laser cutting, the blank shall be annealed if the micro hardness
is > 500 HV in the heat affected zone, in order to achieve a hardness of ≤ 500 HV.
5.3.6 Requirements for the connection of the superabrasive section to the blank
5.3.6.1 Connection of segments to the blank
The segments for hand-held cutting-off wheels for dry cutting-off shall be connected to the blank by
welding, sintering, direct melting or infiltration attachment processes.
5.3.6.2 Tolerances and bending moment for segmented non-precision cutting-off wheels
For segmented non-precision cutting-off wheels for the use on hand-held cutting-off machines, the ratio
of segment height to thickness of the blank, X /E shall be ≤ 8,5.
For segmented non-precision cutting-off wheels the strength of the joint between the blank and the
segment or the strength of the segment itself shall be designed to comply with the following bending
moment M :
b
LE⋅ ⋅ σ
vb
M = (1)
b
where
M is the bending moment, expressed in Nm;
b
L is the length of the bond interface between segment and blank, expressed in m;
v
E is the thickness of the blank, expressed in mm;
σ is the bending strength value, expressed in N/mm².
b
The bending strength values to be included in Formula (1) are:
a) for cutting-off wheels for the use on stationary and mobile cutting-off machines: σ = 450 N/mm ,
b
and
b) for cutting-off wheels for the use on hand-held cutting-off machines σ according to Table 11. Both
b
values for the minimum bending strength and minimum bending moment shall be achieved.
Table 11 — Bending strength σ and bending moment M for cutting-off wheels for the use on
b b
hand-held cutting-off machines
Blank thickness Minimum Minimum
bending bending
moment strength
E M σ
b b
mm Nm N/mm
≤ 1,5 6
1,5 < E < 2 8
≥ 2 10 600
5.3.6.3 Bending moments for cutting-off wheels with continuous cutting rim in metal bond
For non-precision cutting-off wheels with continuous rim, the strength of the joint between the metal
bond and the blank or within the abrasive layer shall be designed to comply with the following bending
moment M :
b
M = F × D / 2 (2)
b
where
M is the bending moment, expressed in Nm;
b
F is the force, here: F = 125 N;
D is the outside diameter of the cutting-off wheel, expressed in m.

5.3.6.4 Requirements for reconditioned non-precision cutting-off wheels
Segmented cutting-off wheels which have been equipped with new abrasive sections due to wear of the
abrasive sections shall comply with the same requirements as unused cutting-off wheels.
They shall comply with the marking requirements in Annex A and in addition carry the data for marking
the reconditioned state given in C.2.
Reconditioning is only permitted, if the preconditions in C.1 are complied with.
5.3.7 Tensioning of non-precision cutting-off wheels
All non-precision cutting-off wheels, marked with maximum operating speed of 100 m/s for hand-held
cutting-off machines and blank diameter in the range of 260 mm to 400 mm shall be in a tensioned state
in order to minimize the risk of wobbling (excessive vibration).
The exact position of the neutral point depends on blank type and blank thickness and shall have a
value in the range of 90° to 160° from position (B) (Figure 11) in order to have a correct tensioning of
the non-precision cutting-off wheel.
5.3.8 Limitation of side coating of abrasive grain and/or superabrasive grain
Side coating of abrasive grain and/or superabrasive grain is only allowed at the periphery of the blank
within a limit ≤ 0,05 D (see figure 3) for all non-precision cutting-off wheels marked with maximum
operating speed of 100 m/s for hand-held cutting-off machines and blank diameter in the range of
260 mm to 400 mm.
Key
D outside diameter
Figure 3 — Limitation of side coating (≤ 0,05 D)
5.4 Requirements for diamond wires
5.4.1 General
Wires with diamond or materials with comparable properties are used on wire sawing machines for
sawing (cutting-off) of natural stone, industrial ceramics, concrete and other materials. Diamond wires
shall not be used on hand-held machines.
5.4.2 Requirements
5.4.2.1 Requirements for the support cable
Support cables for diamond wire are subject to frequent breakage due to mechanical stress or wire
fatigue, depending on their construction, type of application and their operating conditions. Therefore, a
cable shall be selected which has proven fatigue resistance, e.g. preferably a multi-strand cable made of
fine multiple wires, for example: 6 × 7 on a 19 wire core.
Support cables shall have a minimum tensile strength of 800 N/mm in relation to the wire diameter.
5.4.2.2 Requirements for spring mounted diamond wire
For diamond wires where the abrasive beads are held by means of springs, press rings and spacer rings,
the bore diameters of the abrasive beads shall have the following limit deviations:
a) for the new diamond wire: bore of the abrasive beads by 0,4 mm greater than the wire diameter;
b) for the used diamond wire: bore of the abrasive beads by 0,6 mm greater than the wire diameter.
A maximum of 5 abrasive beads shall be mounted between two press rings.
After mounting on the support cable, the support cable and the press rings shall not show any sign of
breakage.
The spring ends shall be close-coiled and ground at each end.
5.4.2.3 Requirements for plastic and vulcanised rubber mounted diamond wires
All abrasive beads shall be mounted on the support cable by means of plastic or vulcanized rubber.
5.4.2.4 Requirements for wire couplings and press rings
The wire couplings shall be capable of withstanding at least 30 % of the load capacity of the support
cable.
The press rings shall be capable of withstanding / the load capacity of the support cable without
moving.
5.4.3 Maximum operating speeds
The maximum operating speed for diamond wires shall not exceed v = 40 m/s.
s
5.5 Requirements for mounted points
5.5.1 Spindle diameter tolerances
The tolerance class for spindle diameters for mounted points is given in ISO 22917.
5.5.2 Sequence of maximum operating speeds
Mounted points shall be manufactured for maximum operating speeds conforming to the following
sequence:
5 — 6 — 8 — 10 — 12 — 16 — 20 — 25 — 32 — 35 — 40 — 45 — 50 — 63 in m/s
NOTE For conversion of peripheral speeds into speeds of rotation for different outside diameters D of the
abrasive product, see Annex D.
5.5.3 Safety factors
Mounted points shall have a safety factor against bursting due to centrifugal forces of S = 3. The
br
spindle shall have a safety factor against deflection of S = 1,3. Further requirements see Annex B.
ab
5.6 Requirements for other superabrasive products for non-precision grinding
5.6.1 Bore diameter tolerances
The tolerance class for bores for other superabrasive products for non-precision grinding is H9 for bore
sizes H ≤ 80 mm and H7 for bore sizes H > 80 mm.
5.6.2 Sequence of maximum operating speeds
Other superabrasive products for non-precision grinding shall be manufactured for maximum
operating speeds conforming to the following sequence:
40 — 45 — 50 — 63 — 80 — 100 in m/s
NOTE For conversion of peripheral speeds into speeds of rotation for different outside diameters D of the
abrasive product, see Annex D.
5.6.3 Safety factors
Other superabrasive products for non-precision grinding shall have a safety factor against bursting due
to centrifugal forces at their maximum operating speed as given in Table
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