ISO INTERNATIONAL 296 STANDARD Second edition 1991-04-01 Machine tools - Self-holding tapers for tool shanks Machines-outils - Cones pour emmanchements d'outils a faible conicite Reference number ISO 296:1991(E) Copyright International Organization for Standardization Not for Resale ISO 296:1991(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 International organizations, govern- represented on that committee. mental and non-governmental, in liaison with isO, also take part in the work. Iso ( closely with the International Electrotechnical collaborates ( 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 interna- tional Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard Iso 296 was prepared by Technical Committee ISO/TC 39, Machine tools. edition This second edition cancels and replaces thefirst (IsO 296:1974), of which it constitutes a technical revision. ISO 1991 All rights reserved. No part of this publication may be reproduced or utilized In any form or by any means, electronlc or mechanical, including photocopying and microfilm, without permission In writing from the publisher. Internatlonal Organization for Standardization Case Postale 56: CH-1211 Geneve 20 · Switzerland Printed in Switzeriand for Standardizatior No reproduction or networking permited without iense from IHS Not for Resale ISO 296:1991(E) INTERNATIONAL STANDARD Machine tools -- Self-holding tapers for tool shanks 1 Scope Table 1 Tapers Sizes in Designation Sizes in inches millimetres This International Standard specifies the dimensions Nos. 4 and 6 Nos. 1 to 3 of self-holding tapers for tool shanks with a small Small tapers metric and No. Brown & Sharpe taper of about 4 % to 5 %, classified, according to 0 Morse their use, into the three following catergories: Tapers for gen- Nos. 1 to 6 Morse1) a) tapers for general use; eral use b) smaller tapers; Nos. 80 to 200 Large tapers metric c) larger tapers. 1) Except for threads, Nos. 1 to 6 Morse tapers, For the first category, tapers recommended by iso manufactured either to metric values or to inch val- are Nos. 1 to 6 Morse tapers. Their standard sizes ues, are strictly interchangeable, though not abso- lutely identical. in millimetres are given in table 2, and the corre- sponding sizes in inches are given in table 3. This International Standard provides, for those ele- For smaller and larger tapers, those recommended ments which are threaded, two entirely distinct by Iso are, on the one hand, Nos. 4 and 6 metric types of product according to the type of thread, M 5 % tapers and No. 0 Morse taper, and on the other or UNC. hand, Nos. 80 to 200 metric 5 % tapers. the sizes of which, in millimetres only, are given in table2. In order to distinguish between those two types, it is However, it was agreed to include in parallel, in the important that the element itself be marked with the category of small tapers, Nos. 1 to 3 Brown & Sharpe corresponding thread symbol and the type of taper tapers, the sizes of which, in inches only, are given symbol, as shown in the figures in clause 4. in table 3. Lastly,this International Standard specifies the di- Consequently, as shown in table 1, the self-holding mensions of grooves and holes necessary for the tapers dealt with in this International Standard in- design of tapers for applications where coolant sup- clude ply is required. a) for general use, only Nos. 1 to 6 Morse tapers; b) for sizes below No. 1 Morse taper, two solutions. 2 Normative reference i.e. e