ISO INTERNATIONAL 722 STANDARD Third edition 1991-02-15 Rock drilling equipment -- Hollow drill steels in bar form, hexagonal and round Materiel de forage des roches --- Barres creuses, hexagonales et rondes pour fleurets Reference number 1SO 722:1991(E) Not for Resale ISO 722:1991(E) Foreword Iso (the Internationat 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 technicai committee has been established has the right to be represented on that committee. International organizations, govern- mental 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 Inter- bodies casting a vote. International Standard isO 722 was prepared by Technical Committee ISO/TC 82, Mining. This third edition cancels and replaces the second edition (IsO 722: 1985), which has been technically revised (addition of round drill steels and extension of the range of sizes). ISO1991 All rights reserved. No part of this pubication may be 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 Case Postale 56.CH-1211 Geneve 20Switzerland Printed in Switzerland ii Copyright International Organization for Standardization Not for Resal ISO 722:1991(E) INTERNATIONAL STANDARD Rock drilling equipment -- Hollow drill steels in bar form, hexagonal and round Scope This International Standard specifies the dimensions of hexagonal and round drill steels in bar form used for rock drilling. Dimensions The dimensions for hollow hexagonal and round drill steels in bar form shall comply with the dimensions given in figure1 and table1 and in figure2 and fable 2, respectively. 2.1 Hexagonal drill steels Figure 1 Table 1 Dimensions in millimetres d R Nominal size e *1 Size Tolerance approx. min. 19 19,2 21,4 5,5 1,5 1,5 -0.4 22 22,4 24,8 6,1 2 1,5 -0.6 25 25,6 28,5 6,8 2 1,5 -0, 28 28,9 31,9 8,3 3 1,5 -0. 32 32,3 35,2 8,8 3,2 2,4 38 38,65 42,6 13 3,2 2,4 -1. 45 49,2 14,5 4,5 3,2 45,4 Copyright International Organization for Standardization censefromIHS Not for Resale