isO INTERNATIONAL STANDARD 10899 First edition 1996-12-15 High-speed steel two-flute twist drills -- Technical specifications Forets helicoidaux a deux levres en acierrapide-Spécifications techniques ISO Reference number ISO10899:1996(E) Copyright Intermational Organization for Standardization cense with 1 mitted without license from IHS Not for Resale ISO10899:1996(E) Contents Page Scope 1 2 Normative references 1 3 Definitions 1 4 General features of design 2 5 Dimensions. 2 5.1 Drill diameter 2 5.2 Cylindrical shank 2 5.3 Taper shank 2 5.4 Radial runout, 2 5.5 Lengths 3 5.6 Web thickness 4 5.7 Web symmetry 4 5.8 Land width. 6 5.9 Relative lip heights 7 5.10 Flute spacing 8 5.11 Twist drill angles. 8 6 Materials and hardness 9 6.1 Cutting portion 6 6.2 Shank.. 6 Surfacefinish. 6 8 Marking.. 10 Annexes Cone angle tolerances of AT7 quality.. 11 B Web symmetrymeasurement 12 c Bibliography 13 @ISO1996 reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization CasePostale56.CH-1211Geneve20.Switzerland Printed in Switzerland Copyright Intermational Organization for Standardization Not for Resale @ISO 1SO 10899:1996(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 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. 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. International Standard ISO 10899 was prepared by Technical Committee ISO/TC29. Small tools, Subcommittee Sc 2, Drills, reamers, milling cutters and milling machine accessories. and C are for information only. ili Copyright Intemational Oorganizatin for Standardization ed without license from IHS Not for Resale