ISO INTERNATIONAL STANDARD 20318-2 First edition 2019-03 Mechanical pencils and leads for general use Classification, dimensions, quality and test methods - Part 2: Black leads Porte-mines et mines pour usage general- Classification, dimensions, qualite et méthodes d'essai Partie2:Mines graphitepourporte-mines Reference number IS020318-2:2019(E) ISO @IS0 2019 IS020318-2:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ISO2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below orIso's memberbody in the countryof therequester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone:+41227490111 Fax:+4122749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019- All rights reserved IS020318-2:2019(E) Contents Page Foreword ..iv Introduction.. 1 Scope.. 2 Normative references ... 3 Terms and definitions 4 Classification 2 5 Quality.. .2 5.1 Bending strength .2 5.2 Hardness degree ..3 6 Dimensions. .3 7 Test methods. ..4 7.1 Test conditions .4 7.2 Bending strength 4 7.3 Hardness degree. .5 7.3.1 General. .5 7.3.2 Writing density .5 7.3.3 Writing test. .9 7.4 Dimension. 9 7.4.1 Diameter 7.4.2 Length. .9 8 Designation ..10 Bibliography .11 @ IS0 2019 -All rights reserved iii