Reference number  
DRS  426:2019  
© RSB 2019  
 
 
 RWANDA 
STANDARD  DRS 
426 
 
1st edition  
2019 -mm-dd 
 
Furniture — Chairs and tables for 
educational institutions  —Functional size 
and performance requirements  
 
 
 
  DRS 426 :2019  
©RSB 2019 - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB 2019  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reprodu ce this document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw   
ePortal: www.portal.rsb.gov.rw   DRS 426:2019  
iii                ©RSB 2019  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ....................  v 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  1 
4 Functional sizes requirements  ................................ ................................ ................................ .... 5 
4.1 Types  ................................ ................................ ................................ ................................ .............  5 
4.2 Dimensions  ................................ ................................ ................................ ................................ ... 5 
4.3 Size................................ ................................ ................................ ................................ .................  6 
4.4 Appearance and surface fin ish ................................ ................................ ................................ . 17 
5 Performance requirements  ................................ ................................ ................................ ........  17 
5.1 Requirements for tables  ................................ ................................ ................................ ............  17 
5.1.1  Corn ers of table tops  ................................ ................................ ................................ .................  17 
5.1.2  Edges of table tops  ................................ ................................ ................................ ....................  17 
5.1.3  Height and working angle of table tops  ................................ ................................ ...................  18 
5.2 Single tables for general use  ................................ ................................ ................................ .... 18 
5.3 Dual tables for general use, typing tables and science tables  ................................ ..............  18 
5.3.1  Dimensions  ................................ ................................ ................................ ................................ . 18 
5.3.2  Performance of dual tables  ................................ ................................ ................................ ....... 18 
5.3.3  Performance of typing and science tables  ................................ ................................ ..............  18 
5.4 Drawing table  ................................ ................................ ................................ ..............................  18 
5.4.1  Basic dimensio ns ................................ ................................ ................................ .......................  18 
5.4.2  Additional requirements for design  ................................ ................................ ..........................  19 
5.4.3  Performance of small drawing tables  ................................ ................................ .......................  19 
5.4.4  Performance of large drawing tables  ................................ ................................ .......................  19 
5.5 Needlework, arts and crafts, and nursery school tables  ................................ ........................  19 
5.5.1  Basic dimensions  ................................ ................................ ................................ .......................  19 
5.6 Specific R equirements for Teachers' desks  ................................ ................................ ............  19 
5.6.1  Basic dimensions  ................................ ................................ ................................ .......................  19 
5.6.2  Pedestals  ................................ ................................ ................................ ................................ ..... 19 
5.6.3  Drawers  ................................ ................................ ................................ ................................ ....... 19 
5.6.4  Performance  ................................ ................................ ................................ ................................  20 
5.7 Specific requirements for chairs and stools  ................................ ................................ ...........  20 
5.7.1  Chairs for general use ................................ ................................ ................................ ................  20 
5.8 Laboratory stools  ................................ ................................ ................................ .......................  20 
5.8.1  Basic dimensions  ................................ ................................ ................................ .......................  20 
5.8.2  Performance  ................................ ................................ ................................ ................................  20 
6 Inspection and test methods for stability, strength and durability  ................................ ....... 20 
6.1 Inspection  ................................ ................................ ................................ ................................ .... 20 
6.2 Sequence of tests  ................................ ................................ ................................ .......................  21 
6.3 Impact resistance test for desk and table tops  ................................ ................................ ....... 21 
6.3.1  Apparatus  ................................ ................................ ................................ ................................ .... 21 
6.3.2  Procedure  ................................ ................................ ................................ ................................ .... 21 
6.4 Static load resistance test for single tables  ................................ ................................ ............  22 
6.5 Static load resistance test for dual and drawing tables  ................................ .........................  22 
6.6 Deflection resistance test for table tops  ................................ ................................ ..................  22 
6.6.1  Apparatus  ................................ ................................ ................................ ................................ .... 22 
6.6.2  Procedure  ................................ ................................ ................................ ................................ .... 22 
6.7 Securing test for desk and table tops  ................................ ................................ ......................  22 DRS 426 :2019  
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 6.8 Drawer load test  ................................ ................................ ................................ .........................  22 
6.9 Backward tippi ng test for chairs and stools  ................................ ................................ ...........  23 
6.9.1  Apparatus  ................................ ................................ ................................ ................................ ... 23 
6.9.2  Procedure  ................................ ................................ ................................ ................................ ... 23 
6.10  Test for colour s tability of thermoplastics shells and table tops  ................................ .........  23 
7 Marking  ................................ ................................ ................................ ................................ ....... 23 
 DRS 426:2019  
v                ©RSB 2019  - All rights reserved  
 Foreword   
Rwanda Standard s are prepared  by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards adopted 
by Technical committ ees are ratifie d by me mbers of RSB Board of Director s for publication and gazettment as 
Rwanda Standards.  
DRS 426 was prepared by Technical Committee RSB/TC 54, Timber, furniture and engineered wood . 
In the preparation of this standard, reference was made to the followin g standard:  
1) SANS 660, Classroom furniture specification  
2) BS EN 1729 -1:2015,  Furniture — Chairs and tables for educational institutions  
3) ISO 5970:1979, Furniture – Chairs and tables for educational institutions – Functional sizes  
The assistance de rived from the above source is hereby acknowledged with thanks.  
Committee membership  
The following organizations were represented on the Technical Committee on Timber, Furniture and Engineered 
wood  (RSB/TC 54) in the preparation of this standard.  
Action pour le Development de l`Artisanat au Rwanda (ADARWA)  
Association pour la défense des droits des consommateurs au Rwanda  (ADECOR)  
Association pour la Promotion des Artisans du Bois  (APROAB)  
GiZ Eco—Emploi  
Integrated Polytechnic Regional Centre (IPRC) — KITABI  
Kalka and Partners Ltd  
MANUMETAL  
MASS DESIGN  
Ministry of Trade and Industry (MINICOM)  DRS 426 :2019  
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 National Industrial Research and development Agency (NIRDA)  
New Forest Company (NFC)  
REAL Contractors  
Rwanda Education Board (REB)  
Rwanda Environment Management Authority (RE MA) 
Rwanda Public Procurement Authority (RPPA)  
Rwanda Water and Forestry Authority (RWFA)  
Rwanda Wood Association  
STRAW Tech  
University of Rwanda — College of Agriculture, Animal Science and Veterinary Medicine ( UR — CAVM)  
University of Rwanda — College of Science and Technology (UR — CST)  
Rwanda  Standards Board  (RSB) — Secretariat  DRS 426:2019  
vii                ©RSB 2019  - All rights reserved  
 Introduction   
Despite the Rwandan growth trend, the wood sector has not been implemented as required to produce high 
quality wood products and vigorous competitive market. The quality of wooden furniture is highly affected by 
the quality of timber, standardized producti on chain, quality control mechanism and grading rules. The lack of 
aforesaid factors results into market dominated by poor quality wooden furniture, compromised safety and unfair 
competition at the market.  
The emerging market dynamics show that consumer’s preferences have gradually shifted from furniture made 
by local timbers to the imported ones, which  is considered as a limiting factor to the development and growth of 
the wood economy in Rwanda.  
To ensure a positive trade balance in wood market there is a  dire need to improve and ensure quality of domestic 
wood products.  
This Draft Standard is one of the series of standards on furniture in Rwanda. The series currently consists of 
the following:  
DRS 413:2019 Furniture — Quality and grading of wooden furnit ure (Under development ) 
DRS 424:2019 Furniture — Specifications for bedsteads  (Under development ) 
DRS 425:2019 Furniture — Storage units — Functional sizes, stability, strength and durability for storage units  
(Under development ) 
DRS 426:2019 Furniture — Chairs and tables for educational institutions — Functional sizes, strength, durability 
and stability  for seating and tables  (Under development ) 
Furniture — Chairs and tables for home furniture — Functional sizes, strength, durability and stability for se ating 
and tables  (Under development ) 
Furniture — Tables — Test methods for the determination of stability, strength and durability  (Under 
development ) 
ISO 7170:2005 Furniture — Storage units — Determination of strength and durability  
ISO 7171:2019 Furnitur e — Storage units — Test methods for the determination of stability  
ISO 7173:1989 Furniture — Chairs and stools — Determination of strength and durability  
 
 DRS 426:2019  
1                ©RSB 2019  - All rights reserved  
 Furniture — Chairs  and tables for educational institutions — 
Part 1: Functional size and performance requirements  
1 Scope  
This Rwa nda standard specifies  performance requirements for seating  and tables in educational institution s. It 
includes requirements for functional sizes, strength, durability and stability.  
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 docu ment. For dated references, only the edition cited applies. For undated references, the 
latest edition of the referenced document (including any amendments) applies.  
ISO 7172,  Furniture – Tables – Determination of stability  
ISO 105 -A02, Textiles -Tests for  colour fastness - Part A02: Grey scale for assessing change in colour  
 
3 Terms and definitions  
For the purposes of this standard, the follow ing terms and definitions apply . 
3.1 
Dual table  
Table used by two or more people  
3.2 
Effective centre of seat (of a chair)  
Intersection of the diagonals of that part of the upper surface of a seat bounded by the sides and front of the 
seat and by the line parallel to the front at the effective depth of the seat  
3.3 
Effective depth of seat (of a chair)  
Distance between the centre of the front edge of a seat and the point of intersection of the seat and the extended 
centre line of the front surface of the backrest   
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 3.4 
Flash line  
Ridge left on a moulded plastics article at the line where the mould halves meet  
3.5 
Height of  seat 
Vertical distance between the horizontal plane on which the chair or stool stands and the effective centre of the 
seat (of a chair) or the top of the seat (of a stool)  
3.6 
Lamin -veneered board  
Composite board that has veneers of either high -pressure or low -pressure decorative laminates of a selected 
type 
3.7 
Lectern  
Removable, hinged writing surface that has a tubular steel frame that attaches to the frame of a chair  
3.9 
Pedestal  
Rectangular cabinet containing drawers  
3.10 
Pellet  
Insert of material tightly fitted , into a counter bored screw or bolt hole using an adhesive, and so set that the 
grain, colour and pattern of the inserted material is continuous with that of the surrounding surface  
3.11 
Self-edging  
Edge -strip or edge -banding of a material t he same as or similar to that of the facing  
3.12 
Shell  
Single -piece moulding comprising a seat and bracket and that can be secured to a chair frame  DRS 426:2019  
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 3.13 
Single table  
Table used by one pupil  or person  
3.14 
Size (of chairs, stools and tables)  
Differentiation  between dimensions within any one type of unit  
3.15 
Solid timber  
Timber that is not built up in thickness but that can be built up in width, by means of bonding  
3.16 
Stackable  
Identical units that, when stacked, partly envelop one another  
3.17 
Stacking bl ock 
Piece of resilient material fixed to the underside of a unit in order to prevent abrasion when units are stacked  
3.18 
Stopper  
Flanged fitting permanently inserted into the end of a tube to seal it off and sufficiently strong to transmit the 
load from t he tube to the bearing surface, without suffering deformation  
3.19 
Surfaces exposed to view  
Surfaces of an assembled unit that may be observed from a normal standing or sitting position when the unit is 
in use  
NOTE Exposed surfaces include the inside of a drawer and any other moveable part in an open position . 
3.20 
Student's bench desk  
Combination of the bench and desk for seating and writing surfaces used in classroom   
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 3.21 
Stool  
Piece of furniture intended for seating without backrest and armrests  
3.22 
Teacher's desk  
Table intended for the use by the teacher with a top writing surface and with a provision of the storage unit 
below the top surface  
3.23 
Educational institution  
Place where people of different ages gain an education, including preschools, ch ildcare, primary -elementary 
schools, secondary -high schools and universities.  
3.24 
Needle work table  
Table used to hold sewing materials  with or without drawers fitted with partitions and supports standing on 
casters.  
3.25 
Drawing table  
Multipurpose desk  which can be used for any kind of drawing, writing or impromptu sketching on a large sheet 
of paper or for reading a large format book or other oversized document or for drafting  precise technical 
illustrations  
EXAMPLE  used e.g.  for engineering or  architectural drawings .  
3.26 
Typing table  
Piece of furni ture with a top  flat surface for typing, a storage unit and castors  
3.28 
Laboratory science table  
Table designed to facilitate the science lab experiments.  DRS 426:2019  
5                ©RSB 2019  - All rights reserved  
 4 Functional sizes  requirements  
4.1 Types  
Furniture for educational institution  shall be of one of the following types:  
a) Tables  
1) Single table for general use,  
2) Dual table for general use,  
3) Drawing table,  
4) Typing table,  
5) Needlework table,  
6) Arts and crafts table,  
7) Science /laboratory table;  
b) Desks :  
1)Teachers' desks;  
2) Student's desk;  
c) Chairs : General purpose chairs ;  
d) Stools ; 
e) Bench ; 
f) Combined bench and table.  
4.2 Dimensions  
The dimensions of educational institutions furniture shall conform to the relevant dimensions given in figure 1 to 
figure 9 , except that where indicated, the dimensions given represent preferred sizes. In such cases other 
dimensions are acceptable . 
Dimensions for seating are given in table 1, and for tables in table 2. The references to the dimensions are 
shown in figure 10 (dimensions in section) and figure 11 (dimensions in plan -view).  
The minimum depth (t 1) and the minimum length ( b1) for tables for single and dual use shall be in accordance 
with table 2.  
The leg clearance zone as defined by dimensions h2, h3, h4, b2, t2, and t3 shall be provided under all tables at 
which students will be seated.  
  
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 4.3  Size 
The size of a table, chair or l aboratory stool shall be designated as A, B, C or D (see figures 1 - 9) and shall 
conform to the height dimensions for tables, chairs and stools provided in figures 3 – 9. 
 
Figure 1: Corner dimensions of table tops, seats and backrests  
 
Note:  
a) T – 18 mm<  T <25 mm  
b) Tolerance: ± 1 mm 
Figure 2: Edge dimensions of table tops, seats and backrests  
 
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 Table 1: Seating (Dimensions in millimetres)  
 
1) h5 is measured to the highest point of the front of the seating area on the centre line.  
2) t4 is measured on the centre line of the seat plane from the front edge to a perpendi cular line from reference point 
W 
3) For size 0, the identification colour and the height of seat only standardized.   
4) h5 is measured to the highest point of the front of the seating area on the centre line   
5) t4 is measured on the centre line of the seat plane from the front edge to a perpendi cular line from reference point 
W  
6) W is the maximum height of foremost point of backrest.  
7) Room for free movement of poster ior in the writing position in the wrong should be ensure d 
8) h6 and h7 are measured on the centre line of the seat plane from the lowest part of the seating surface.  
9) The upper and lower edge of the backrest should be well rounded.  
10) r1 is the approximate radius of the top surface, The curve need not be an exact arc of a circle.  
11) r2 is the radius of the backrest in a horizontal plane.  
12) δ: the main part of the seating surface shall lie between the horizontal and a slope of 4o maximu m, The seating  
surface may be flat or include dishing. Any dishing shall occur in the back two -thirds of the effective seat depth. The  
deepest part of dishing shall occur at the back part of the effective seat depth.  
13) β is the angle between the horizont al and plane of the backrest between h7 and W is not defined.  
 Identification  Sizemark  0 1 2 3 4 5 6 
Age 3-4 4-5 6-7 8-10 11 -13 14- 18 Adult  
Reference stature - average body height  900 1,050  1200  1350  1500  1650  1800  
h5  Height of seat(2) (tolerance +  10) 220 260 300 340 380 420 460 
t4  Effective depth of seat(3) (tolerance + 10) -- 260 290 330 360 380 400 
b3  Minimum width seat  -- 250 270 290 320 340 360 
W  Reference point for β(4) -- 160 170 190 200 210 220 
 h6  Maximum height to bottom of backrest  max -- 120 130 150 160 170 190 
min -- 210 250 280 310 330 360 
h7 Height to top of backrest(6) -- 250 280 310 330 360 400 
b4  Minimum width of backrest(7) -- 250 250 250 280 300 320 
r1  Radius of front edge of the seat(8) -- 30 to 50  30 to 50  30 to 50  30 to 50  30 to 50  30 to 50  
r2 Minimum radius of backrest(9) -- 300 300 300 300 300 300 
δ Angle of seat (10) -- 00 to 40 00 to 40 00 to 40 00 to 40 00 to 40 00 to 40 
β Inclination of back rest(11) -- 950 to 1060 950 to 
1060 950 to 
1060 950 to 
1060 950 to 
1060 950 to 
1060 DRS 426:2019  
15                ©RSB 2019  - All rights reserved  
 Table 2: Tables (Dimension in millimetres)  
 
 
 
1) h1 : Table top surfaces specified in this Standard are national. However, should an inclined surface be required an 
inclination of 100 to 160 is recommended. The edge towards the pupil shall stay at approximately the same height 
as when the table is horizontal.  
2) h1  — h2 : If the shelf is provided within this zone, the opening should be  not less than 60 mm high.  
3) Table 2 gives the preferred  sizes of the minimum depth and length of table tops. For standardization purposes it is 
recommended that these sizes be applied. However, if it is necessary to deviate from these sizes, the following 
incremental sizes should be used  
 
Size b1: from 450 mm to 800 mm: 50 mm increment  
               from 800 mm to 2 000 mm : 100 mm increment  
              Size t1:  from 450 m to 1 200 mm : 50 mm  increment  Identification  Size mark  0 1 2 3 4 5 6 
Age 3 -4 4 -5 6 -7 8 -10 11 -13 14 -18 Adult  
Reference stature - average body height  900 1,050  1200  1350  1500  1650  1800  
h1  Height of top(2/3) (tolerance +  10) 400 460 520 480 640 700 460 
h2  Minimum height of legroom3) -- 350 410 470 530 590 400 
h3 Minimum height of knee zone  -- 350 350 400 400 450 360 
h4 Minimum height of tibia zone  -- 250 250 300 300 350 220 
t1  Maximum depth of tio4)   -- 450 500 500 500 500   
 b1  Minimum length of top4) single table  -- 600 600 700 700 700 190 
Double table  -- 1200  1200  1300  1300  1300  360 
b2 Minimum width of knee zone  -- 450 470 470 470 470 400 
t2  Minimum depth of knee zone  -- 300 300 300 350 400 300 
t3  Minimum depth of tibia zone  -- 400 400 400 400 450 400   
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Figure 10: Dimensions in section  
 
DRS 426:2019  
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Figure 11: Dimension in plan  
4.4 Appearance and surface finish  
The appearance and finish of classroom furniture shall have no defects.  
5 Performance r equirements  
5.1 Requirements for tables  
Stability of tables shall be determined in accordance with principles outlined in ISO 7172.  
5.1.1  Corners of table tops  
Corners of table tops shall have a radius that conforms to that shown in figure 1.  
5.1.2  Edges of table tops  
Edges of table tops shall conform to the profile shown in figure 2.  
 
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 5.1.3  Height and working angle of table tops  
Tables shall either have different fixed heights as shown in figure 3 or, when so required, shall be adjustable in 
height and shall have acceptable locking mechanisms. Tops shall also be either in a fixed horizontal position or 
adjustable to other angles, as required, and in the case of adjustabl e tops, shall have acceptable locking 
mechanisms .  
5.2 Single tables for general use  
Single table meeting functional sizes illustrated in figure 3, shall be such that w hen tested :  
a) In accordance with   6.3, the horizontal displacement of the top from its ori ginal position does not exceed 5 
mm,  
b) In accordance with 6.4, no deformation, gap, fracture or apparent loosening of a joint intended to be rigid 
develops,  
c) In accordance with 6.6, the recorded deflection does not exceed 0,5 mm per 0,1 m2 of area of the top being 
tested, and  
d) In accordance with 6.7, no loosening of the top at any securing point is evident.  
5.3 Dual tables for general use, typing tables and science tables  
5.3.1  Dimensions  
Dimensions of dual tables, typing tables and science tables shall be as given in figure 4.  
5.3.2  Performance of dual tables  
In addition to complying with the requirements of 5.2, a dual table shall be such that, when it is tested in 
accordance with 6.5, the table successfully withstands the static load and overbalancing forces applied .  
5.3.3  Performance of typing and science tables  
The requirements given in 5.2 shall apply . 
5.4 Drawing table  
5.4.1  Basic dimensions  
The basic dimensions of drawing tables shall be as given in fig ure 5(a) or figure 5(b) .  DRS 426:2019  
19                ©RSB 2019  - All rights reserved  
 5.4.2  Additional requirements for design  
Drawing tables shall be adjustable in height, the angle of each top shall be adjustable (when required) and an 
acceptable locking mechanism shall be provided for each adjustment system .  
5.4.3  Performance of small drawing tables  
The requirements given in 5.2 shall apply . 
5.4.4  Performance of large drawing tables  
In addition to complying with the requirements of 5.2, a large drawing table shall be such that, when it is tested 
in accordance with 6.5, the table successfully withstands the static load and overbalancing  forces applied .  
5.5 Needlework, arts and crafts, and nursery school tables  
5.5.1   Basic dimensions  
The basic dimensions of needlework, arts and crafts, and nursery school tables shall be as given in figure 6.  
5.5.2 Performance  
The requirements given in 5.2 shall apply . 
5.6 Specific Requirements for Teachers' desks  
5.6.1  Basic dimensions  
The basic dimensions of teachers' desks shall be as given in figure 7(a) or figure 7(b).  
5.6.2  Pedestals  
Pedestals shall be either an integral part of the desk or shall be a removable unit that, when fixed in position 
within the frame of the d esk, appears to be integral part of  it.  
5.6.3  Drawers  
Drawer fronts shall be of acceptable solid hardwood, and the sides and backs shall be of either acceptable 
hardwood or acceptable softwood. The fronts, sides and backs shall be grooved for plywood or hardboard 
bottoms. The sides shall extend past the back for a distance of at least 75 mm, and one of the following systems 
of guides shall be provided :  
a) two hardwood guide beads to each drawer, so secured within the pedestal as to engage the grooves cut in 
each side of the drawer; or   
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 b) two hardwood guide beads that are secured to the drawer bearers and that work against distance pieces (of 
minimum thickness 6 mm) secured to the bottom edge of the sides of  the drawer; or  
c) as in (b) above, but without distance pieces.  
5.6.4  Performance  
A desk shall be such that, when a drawer is tested in accordance with 6.8, the desk is capable of withstanding 
the test without becoming damaged or deformed . 
5.7 Specific requirements for chairs and stools  
5.7.1  Chairs for general use  
5.7.1.1  Basic dimensions  
The basic dimensions of chairs for general us e shall be as given in figure 8.  
5.7.1.2  Performance  
A chair shall be such that  
a) when tested in accordance with 6.9 and 6.10, no spreading of the legs, damage to the frame or loosening of 
fasteners occurs, and  
b) W hen tested in accordance with 6.10, the shell shows no sign of permanent set, whitening or cracking.  
5.8 Laboratory stools  
5.8.1  Basic dimensions  
The basic dimensions of lab oratory stools shall be as given in figure 9.  
5.8.2  Performance  
A stool shall be such that when tested in accordance with 6.9 and 6.10  no spreading of the legs, damage to 
the frame or loosening of fasteners occurs .  
6 Inspection and test methods for  stability, s trength and durability  
6.1 Inspection  
Visually examine and measure each unit in the sample for compliance with the requirements of the specification 
for which tests to assess compliance are not given in 6.3 to 6.10 . DRS 426:2019  
21                ©RSB 2019  - All rights reserved  
 6.2 Sequence of tests  
Carry out the applicable t ests on each test specimen in the sequence in which they are given. Should a failure 
occur during the sequence of tests, deem the specimen concerned to be defective and no further tests need be 
performed on it.  
6.3 Impact resistance test for desk and table to ps 
6.3.1   Apparatus  
a) A test rig that consists essentially of a frame structure to which the desk or table under test can be firmly 
secured to avoid movement, and a means of applying a vertical downward force of 1 000 N ± 10 N.  
b) A piece of mass 25 kg ± 1 kg to be  suspended by means of a cord.  
c) Cord of reasonable strength  to suspend at least 26 kg and length  of at least 1 m  to hold the mass piece 
referred to in (b) above.  
d) Felt of width and length each approximately 500 mm , and of thickness at least 10 mm.  
e) Chocks of suitable size to restrain the horizontal movement of the desk legs.  
6.3.2  Procedure  
a) Place the desk or table in the test rig and restrain the horizontal movement of the legs by securing (in an 
acceptable manner ) the chocks against the bottoms of the legs.  
b) Without disturbing the balance of the desk or table, apply a vertical force of 1 000 N ± 10 N to the top, and 
secure the top firmly to avoid  movement during the test.  
c) Using the cord, suspend the mass pi ece 1 m ± 0 , 01 m vertically above one end of the desk or table t op. 
d) Place the piece of felt on the edge at the end of the desk or table top.  
e) Raise the mass piece through an arc that the cord makes an angle of 45° to the vertical, then release the 
mass piece and allow it to strike the felt.  
f) Subject each end of the desk or table top to 25 such impacts.  
g) Check for horizontal displacement of the top from its original position.  
h) Check for complian ce with requirement 5.2 (a).  
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 6.4 Static load resistan ce test for single tables  
Place the table in the normal position on a level surface and apply, for at least 1 min, a force of 500 N distributed 
over an area of 150 mm x 150 mm in the approximate centre of the table top. Check for compliance with 
requireme nt 5.2(b).  
6.5  Static load resistance test for dual and drawing tables  
For a period of 1 min, apply two forces, each of 500 N and each distributed over an area of 150 mm × 150 mm, 
at two points in the approximate centre of each half of the table top. Check for compliance with the requirements 
of 5.3.2 an d 5.4.4. 
6.6  Deflection resistance test for table tops  
6.6.1  Apparatus  
a) A straight edge of length at least equal to that of the table.  
b) A feeler gauge or other acceptable means of measuring deflection.  
6.6.2  Procedu re  
a) Subject the table top to a force of 100 N applied perpendicularly to the centre of the surface.  
b) So place the straight edge across the table top that it rests on the edges of the table top.  
c) Measure the maximum vertical deflection between the table top and the lower surface of the straight edge.  
d) Record the deflection to the nearest 25 mm.  
e) Check for compliance with the requirement of 5.2(c). 
6.7 Securing test for desk and table tops  
Stand the desk or table upon a plane surface. Attach a mass  piece of  20 kg ± 0,1 kg to a leg. Using a suitable 
apparatus attached to the corner of the top nearest to the loaded leg, raise the end of the desk or table 
approximately 250 mm from the supporting p lane, and lower to its original position. Repeat this operation 250 
times, and check for compliance with the requirement of 5.2(d).  
6.8 Drawer load test  
With the desk in the normal working position, extend the drawer to the fully open position . DRS 426:2019  
23                ©RSB 2019  - All rights reserved  
 A drawer shou ld be extended for at least 80 % of the travel of which it is capable, before the guides become 
disengaged place a mass piece of 25  kg ± 1 kg on the middle of the top edge of the drawer front and, after a 
period of 1 min, remove the mass piece and examine the desk for compliance with the requirement of 5.6. 
6.9 Backward tipping test for chairs and stools  
6.9.1  Apparatus  
A test rig capable of accommodatin g a chair or stool  and allowing it to fall backwards freely through 90° onto a 
flat solid surface covered with high density foam rubber of nominal thickness 15 mm.  
6.9.2  Procedure  
a) Attach the rear legs of a chair or stool, or in the case of a stool without a backrest, two adj acent legs to the 
test rig.  
b) Allow the chair or stool to so fall backwards from a point where it is just out of equilibrium onto the foam / 
rubber, that the chair's backrest or the edge of the stool's seat strikes the foam/ rubber cushion.  
c) Repeat this  operation 30 times.  
d) Examine the chair or stool for compliance with the requirements of  5.7. 
6.10 Test for colour stability of thermoplastics shells and table tops  
Use an acceptable colour stability test method and expose the specimen for 72 h. Then use th e grey scale 
described in ISO 105 -A02 for assessing the change in colour, and determine and record the light fastness rating 
of the specimen . 
7 Marking  
Each table, desk, chair and stool shall bear the following information in clear and legible marking and i n a 
manner that will not impair the finish or strength (or both) of the article. On the underside of table tops or under 
the seat of chairs and stools there must be:  
1) the manufacturer's name, trade name or trade mark;  
2) the date of manufacture or the production batch identification number or letter.   
©RSB 2019 - All rights reserved                  24 
 Bibliography  
[1] DUS/1915 , School Furniture -Specification,  2018 
[3] ISO 4470 , Moisture content of timber (electric moisture -meter method)  
[4] ISO 2808, Paints and varnishes – Determination of film thickness  
[5] ISO 3668, Paints and varnishes – Visual comparison of the colour of paints.  
[6] ISO 12578 , Timber structures - Glued laminated timber - Component performance requirements  
 
 DRS 426:2019  
ICS 97.140  
©RSB 2019  - All right s reserved