ISO 21015:2007

INTERNATIONAL ISO
STANDARD 21015
First edition
2007-06-15

Office furniture — Office work chairs —
Test methods for the determination of
stability, strength and durability
Mobilier de bureau — Sièges de travail de bureau — Méthodes d'essai
pour la détermination de la stabilité, de la résistance et de la durabilité




Reference number
ISO 21015:2007(E)
©
ISO 2007

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ISO 21015:2007(E)
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ISO 21015:2007(E)
Contents Page
Foreword. iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 General test conditions. 2
4.1 Preliminary preparation . 2
4.2 Test equipment . 3
4.3 Application of forces . 3
4.4 Tolerances . 3
4.5 Sequence of testing. 3
4.6 Inspection and assessment of results. 3
5 Test apparatus . 5
5.1 Test surface. 5
5.2 Stops . 5
5.3 Seat-loading pad. 5
5.4 Smaller seat-loading pad . 6
5.5 Local loading pad . 6
5.6 Back-loading pad. 6
5.7 Arm-rest durability test apparatus . 7
5.8 Strap. 8
5.9 Stability-loading device. 9
5.10 Loading discs. 9
5.11 Test surface for castor durability. 9
6 Loading points . 9
6.1 Loading point A. 9
6.2 Loading point B. 9
6.3 Loading point C. 9
6.4 Loading point D. 10
6.5 Loading point E. 10
6.6 Loading point F. 10
6.7 Loading point G . 10
6.8 Loading point H. 10
6.9 Loading point J . 10
7 Test methods. 11
7.1 Stability . 11
7.2 Static-load tests . 15
7.3 Durability tests . 17
8 Test report . 19
Annex A (informative) Guidance for the choice of forces, cycles, etc., for stability, strength and
durability tests — General principles . 20
Annex B (normative) Seat-loading pad data. 23
Annex C (normative) Stability-loading device data . 26

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ISO 21015:2007(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 21015 was prepared by Technical Committee ISO/TC 136, Furniture.

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INTERNATIONAL STANDARD ISO 21015:2007(E)

Office furniture — Office work chairs — Test methods for the
determination of stability, strength and durability
1 Scope
This International Standard specifies test methods for determining the stability, strength and durability of office
work chairs. Guidance is given on the choice of forces, cycles, etc., for these tests.
The tests are designed to be applied to an article of furniture that is fully assembled and ready for use.
The dimensions in the tests are applicable to office work chairs intended for adult persons.
The tests consist of the application, to various parts of the item, of forces simulating normal functional use, as
well as misuse that can reasonably be expected to occur.
The tests are designed to evaluate properties without regard to materials, design/construction or
manufacturing processes.
The test results are valid only for the article tested. When the test results are intended to be applied to other
similar articles, it is important that the test specimen be representative of the production model.
Tests carried out according to this International Standard are intended to demonstrate the ability of the item to
give satisfactory service in its intended environment. The tests have been developed for units/components
that have not been in use. However, when properly justified, they can be used for fault investigation.
Data are given for the design of seat-loading pads (Annex B) and for the design of stability-loading pad
(Annex C).
This International Standard does not give any product requirements. These can be specified in a requirements
document. If this is not available, possible forces and cycles are suggested in Annex A (informative). These
forces and cycles can be used for adults regardless of their weight and number of working hours.
This International Standard does not specify type approval tests for chair components.
Assessment of ageing and degradation is not included. The tests are not intended to assess the durability of
upholstery, i.e. filling materials and covers.
2 Normative references
The following referenced document is indispensable for the application 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.
ISO 22880:2004, Castors and wheels — Requirements for castors for swivel chairs
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ISO 21015:2007(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
office work chair
piece of seating furniture for one person, with a back rest, with or without arm rests, whose upper part, which
includes the seat, can rotate in the horizontal plane and can be adjusted in height
NOTE Other adjustments may be included.
3.2
column
〈office work chair〉 component that connects the base and the seat structure
NOTE A column normally incorporates a seat-height adjustment and swivel mechanism.
3.3
locking device
device that inhibits the movement of the seat action and/or the back rest
3.4
arm-rest length
distance between vertical lines through its front and rear edges
NOTE In the case of an arm rest that is not horizontal or that is curved, the length is measured in a horizontal plane
20 mm below the highest point of the arm rest.
3.5
supporting point
castor or glide
NOTE There are two castor types as defined in ISO 22880:2004.
a) Type H: Castors with plain wheels defined as type H, hard tread. The wheel is one colour over the entire surface.
These castors are suitable for carpeted floors.
b) Type W: Castors with resilient tyred wheels defined as type W, soft tread. This is of clearly different colour to the
wheel centre. These castors are suitable for hard stone, wooden or tiled floors or those featuring non-
textiled covering.
4 General test conditions
4.1 Preliminary preparation
The unit shall be assembled and/or configured according to the instructions supplied with it. The most adverse
configuration shall be used for each test (see Table 1). For testing a range of related chair models, it is
necessary to test only the worst case(s). If mounting or assembly instructions are not supplied, the mounting
or assembly method shall be recorded in the test report. Fittings shall not be re-tightened unless specifically
required by the manufacturer. If it is necessary to change the configuration to produce the worst case
conditions, any re-tightening of the fittings shall be recorded in the test report.
Unless otherwise stated, all tests shall be carried out on the same sample.
The tests shall be carried out in indoor ambient conditions. If during a test the temperature is outside of the range
of 15 °C to 25 °C, the maximum and/or minimum temperature shall be recorded in the test report.
In the case of designs not addressed in the test procedures, the test shall be carried out as far as possible as
described, and deviations from the test procedure recorded in the test report.
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ISO 21015:2007(E)
Before beginning the testing, visually inspect the unit thoroughly. Record any defects so that they are not
assumed to have been caused by the tests. Carry out measurements if specified.
4.2 Test equipment
Unless otherwise specified, the tests may be applied by any suitable device because results are dependent
only upon correctly applied forces and not on the apparatus.
The equipment shall not inhibit deformation nor cause unnatural deformation of the unit/component, i.e. it shall
be able to move so that it can follow the deformation of the unit/component during testing.
All loading pads shall be capable of pivoting in relation to the direction of the applied force. The pivot point
shall be as close as practically possible to the load surface.
4.3 Application of forces
The forces in the static-load tests shall be applied sufficiently slowly to ensure that negligible dynamic force is
applied. Each force shall be maintained for not less than 10 s and not more than 15 s.
The forces in durability tests shall be applied at a rate to ensure that excessive heating does not occur. Each
force shall be maintained for (2 ± 1) s.
The forces may be applied using masses.
4.4 Tolerances
Unless otherwise stated, the following tolerances are applicable:
a) Forces: ± 5 % of the nominal force;
b) Masses: ± 1 % of the nominal mass;
c) Dimensions: ± 5 mm of the nominal dimension on soft surfaces;
± 1 mm of the nominal dimension on all other surfaces;
d) Angles: ± 2° of the nominal angle.
The accuracy for the positioning of loading pads shall be ± 5 mm.
4.5 Sequence of testing
All applicable tests shall be carried out on the same sample and in the sequence that the clauses are
numbered in this International Standard.
4.6 Inspection and assessment of results
After completion of each test, inspect the unit again. Record any changes including the following:
a) fracture of any component or joint;
b) loosening, which can be demonstrated by hand pressure, of any joint intended to be rigid;
c) deformation or wear of any part or component such that its function is impaired;
d) loosening of any means of fixing components to the unit;
e) changes that can affect stability.
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ISO 21015:2007(E)
Table 1 — Positioning of chair components
Tilt
Seat Back rest Back rest Castors
Clause Test Seat Arm rest Foot rest
stiffness
height in height in depth and base
adjustment
7.1.1 Front edge highest foremost highest foremost maximum most likely most likely —
overturning position position position position tension to cause to cause
overturning overturning
7.1.2 Forwards overturning highest foremost highest foremost maximum most likely most likely —
position position position position tension to cause to cause
overturning overturning
7.1.3 Forwards overturning highest foremost lowest foremost maximum most likely most likely most likely
for chairs with foot position position position position tension to cause to cause to cause
rest overturning overturning overturning
7.1.4 Sideways overturning highest foremost highest foremost maximum most likely — —
for chairs without arm position position position position tension to cause
rests overturning
7.1.5 Sideways overturning highest foremost highest foremost maximum most likely most likely —
for chairs with arm position position position position tension to cause to cause
rests overturning overturning
7.1.6 Rearwards highest rearmost highest rearmost minimum most likely most likely —
overturning of chairs position position position position tension to cause to cause
without back-rest overturning overturning
inclination
7.1.7 Rearwards highest rearmost highest rearmost minimum most likely most likely —
overturning of chairs position position position position tension to cause to cause
with back-rest overturning overturning
inclination
7.2.1 Seat front-edge highest foremost — — — — — —
static-load test position position
7.2.2 Combined seat and highest most highest rearmost mid range least likely — —
back static-load test position adverse position position to cause
position overturning
7.2.3 Arm-rest downward lowest horizontal — — — — most likely —
static-load test – position to cause
central failure
7.2.4 Arm-rest downward lowest horizontal — — — — highest, —
static-load test – front position foremost
position
7.2.5 Arm-rest sideways lowest horizontal — — — — highest, —
static-load test position widest
position
7.2.6 — — — — — —
Foot-rest static-load least likely highest
test to cause position
overturning
7.3.1 Seat and back highest horizontal highest most likely mid range 90° to the — —
durability position and position to cause base arm
foremost failure
7.3.2 Arm-rest durability lowest horizontal — — maximum — highest, —
position tension widest
position
7.3.3 Swivel test highest horizontal, highest rearmost — — — —
position foremost position position
position
7.3.4 Foot-rest durability — — — — — least likely — lowest
to cause position
overturning
7.3.5 Castor and chair-base lowest horizontal — — — — — —
durability position

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ISO 21015:2007(E)
5 Test apparatus
5.1 Test surface
The test surface shall be rigid, horizontal and flat.
5.2 Stops
Stops are devices to prevent the chair from sliding or rolling but not overturning, They shall be 3 mm high for
stability tests and 12 mm high for all other tests, except in cases where the design of the chair or the test
method necessitates the use of higher stops, in which case the lowest that prevents the chair from sliding or
rolling shall be used.
5.3 Seat-loading pad
The seat-loading pad is a naturalistically shaped rigid indenter with a hard, smooth surface (see Figure 1). In
principle, this loading pad is for use in loading points A (6.1) and C (6.3). See Figure 7. For details of the
design, see Annex B.

a
Loading point.
Figure 1 — Seat-loading pad

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ISO 21015:2007(E)
5.4 Smaller seat-loading pad
The smaller seat-loading pad is a rigid, circular object 200 mm in diameter, the face of which has a convex
spherical curvature of 300 mm radius with a 12 mm blend radius between the face and the side. (See
Figure 2). In principle, this loading pad shall be used in loading points D (6.4), G (6.7), F (6.6) and J (6.9). See
Figure 7.
Dimensions in millimetres

Figure 2 — Smaller seat-loading pad

5.5 Local loading pad
The local loading pad is a rigid, circular object 100 mm in diameter, with a flat face and a 12 mm blend radius
between the face and the side.
5.6 Back-loading pad
The back-loading pad is a rigid rectangular object 200 mm high and 250 mm wide, the face of which is curved
across the width of the pad with a convex cylindrical curvature of 450 mm radius and with a 12 mm blend
radius between the face and the sides. (See Figure 3).

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ISO 21015:2007(E)
Dimensions in millimetres

Figure 3 — Back-loading pad
5.7 Arm-rest durability test apparatus
An apparatus capable of applying a cyclic force simultaneously to both arm rests. The forces shall be applied
through an arm-rest loading device, which functions in principle as shown in Figure 4.
Dimensions in millimetres

Key
F loading point
Figure 4 — Arm-rest test principle
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ISO 21015:2007(E)
The apparatus shall be capable of applying the forces at varying angles to the vertical. It shall be adjustable
both vertically and horizontally and set as specified in 7.3.2. The apparatus shall be capable of freely following
the deformation of the arm rests during testing (see Figure 5). The length of the loading pad shall be 100 mm
with the force acting through the centre of its length.
Dimensions in millimetres

Figure 5 — Example of arm-rest loading pad

5.8 Strap
A 50 mm wide strap capable of bearing a mass as specified in 7.1.1 and Annex A.
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ISO 21015:2007(E)
5.9 Stability-loading device
A loading device in principle functioning as shown in Figure 6. For details of the design, see Annex C.

Key
1 hold down strap
2 centreline of seat
F vertical force
1
F horizontal force
2
a
For details, see Figure C.1.
b
For details, see Figure C.2.
Figure 6 — Stability-loading device — Principle
5.10 Loading discs
Loading discs each with a mass of 10 kg, a diameter of 350 mm and a thickness of 48 mm. The centre of
gravity shall be in the centre of the disc.
5.11 Test surface for castor durability
This shall be a horizontal smooth steel surface.
6 Loading points
6.1 Loading point A
This shall be the point in which the chair’s axis of rotation intersects with the seat surface with the seat in a
position as close as possible to the horizontal.
6.2 Loading point B
This shall be the point on the centreline of the back rest, 300 mm above loading point A (6.1), measured when
the seat is loaded with 640 N through the seat-loading pad.
6.3 Loading point C
This shall be a point in front of loading point A (6.1) along the centreline of the seat, 100 mm from the
structure of the seat edge.
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ISO 21015:2007(E)
6.4 Loading point D
This shall be the point 150 mm to the right of loading point A (6.1).
6.5 Loading point E
This shall be the point 50 mm to the right of loading point B (6.2).
6.6 Loading point F
This shall be a point in front of loading point D (6.4) on a line parallel to the centreline, 100 mm from the
structure of the seat edge.
6.7 Loading point G
This shall be the point 150 mm to the left of loading point A (6.1).
6.8 Loading point H
This shall be the point 50 mm to the left of loading point B (6.2).
6.9 Loading point J
This shall be a point in front of loading point G (6.7) on a line parallel to the centreline, 100 mm from the
structure of the seat edge.
Dimensions in millimetres

Key
A to H, J loading points
Figure 7 — Loading points
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ISO 21015:2007(E)
7 Test methods
7.1 Stability
Position the chair on the test surface (see 5.1) with its components as specified in 4.1 and Table 1.
Record whether the chair overturns during the tests in 7.1.1 to 7.1.7.
7.1.1 Front edge overturning
Do not position the chair with the stops against the supporting points (3.5). Fix the strap (5.8) to the chair as
shown in Figure 8, i.e. the force is applied at the point on the front edge that is furthest from the axis of
rotation, and allow the mass to hang freely.


a
Position of the strap on the seat surface.
b
Tilting axis, castors in the most adverse position.
Figure 8 — Front edge overturning

7.1.2 Forwards overturning
Position the chair with two adjacent supporting points (3.5) on the front against the stops (5.2).
Apply by means of the stability-loading device (5.9) a vertical force, F , acting 60 mm from the front edge of
1
the load bearing structure of the seat at those points most likely to result in overturning. Apply for at least 5 s a
horizontal outwards force F from the point on the seat surface where the vertical force is applied (see
2
Figure 9).

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ISO 21015:2007(E)
Dimensions in millimetres

Key
A seat-loading point
F vertical force
1
F horizontal outwards force
2
Figure 9 — Forwards overturning

7.1.3 Forwards overturning for chairs with foot rest
For chairs with foot rests repeat the procedure of 7.1.2 on the foot rest. For round cross-section ring-shaped
foot rests, the force shall be applied through the centre of the ring cross section.
7.1.4 Sideways overturning for chairs without arm rests
Position the chair with two adjacent supporting points (3.5) on one side against the stops (5.2).
Apply by means of the stability-loading device (5.9) a vertical force, F , acting 60 mm from the edge of the
1
load bearing structure of the side nearest the stopped supporting points at those points most likely to result in
overturning. Apply for at least 5 s a horizontal sideways force, F , outwards from the point on the seat surface
2
where the vertical force is applied (see Figure 10).

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ISO 21015:2007(E)
Dimensions in millimetres

Key
A seat-loading point
F vertical force
1
F horizontal sideways force
2
Figure 10 — Sideways overturning for chairs without arm rests
7.1.5 Sideways overturning for chairs with arm rests
Position the chair with two adjacent supporting points (3.5) on one side against the stops (5.2).
Apply by means of the stability-loading device (5.9) a vertical force, F , acting at a point 100 mm from the fore
1
and aft centreline of the seat at the side where the supporting points (3.5) are restrained (see Figure 11) and
between 175 mm and 250 mm forward of the rear edge of the seat. Apply a vertical downward force, F ,
2
acting at points on the arm rest that is on the same side as the restrained supporting points (3.5) up to a
maximum 40 mm inwards from the outer edge of the upper surface of the arm rest, but not beyond the centre
of the arm rest, and at the most adverse position along its length. Apply a horizontal sideways force, F ,
3
outwards from the same point for at least 5 s (see Figure 11).
Dimensions in millimetres

Key
A seat-loading point
F vertical force
1
F vertical downward force
2
F horizontal sideways force
3
Figure 11 — Sideways overturning for chairs with arm rests
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ISO 21015:2007(E)
7.1.6 Rearwards overturning for chairs without back-rest inclination
Position the chair with two adjacent supporting points (3.5) on the back against the stops (5.2). When an
independent lumbar adjustment is fitted, it shall be set in the most adverse configuration.
A vertical force, F , shall be applied at point A (6.1) and a horizontal force, F , shall be applied at point B (6.2).
1 2
See Figure 12.
If the back-rest pad is pivoting around a horizontal axis above the height of the seat and is free to move
...