NTERNATIONAL STANDARD (TSO) 839 / I Milling machine arbors with 7/24 tapers Part : Accessories Arbres porte-fraises au cone 7/24 - Partie Il : Equipements First edition - 1977-08-01 SO 839/11-1977 (E) UDC 621.914.3-229.2 Ref. No. ISO 839/lI-1977 (E) Descriptors : tools, machine tools, milling cutter arbors, accessories, spacers, bearing collars, locknuts, dimensions. Price based on 5 pages Copyright International Organization for Standardization tted without license from IHS Not for Resale FOREWORD ISO (the International Organization for Standardization) is a worldwide federation of national standards institutes (IsO member bodies). The work of developing International Standards is carried out through IsO technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmentai, in liaison with IsO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. Committee International Standard ISO 839/l was developed by Technical It has been approved by the member bodies of the following countries : Australia India Romania Austria Israel South Africa, Rep. of Belgium Italy Spain Switzerland Czechoslovakia Japan France Korea, Rep. of Turkey Germany Mexico United Kingdom Hungary Poland U.S.S.R. No member body expressed disapproval of the document. This International Standard cancels and replaces sub-clauses 3.2 and 4.2 of ISO Recommendation R 839-1968, of which it constitutes a technical revision. @ International Organization for Standardization, 1977 : Printed in Switzerland opyrighIntemationarganizationforStandardizato No reproduction or networking permited without license from IHS Not for Resale ISO 839/lI-1977 (E) INTERNATIONAL STANDARD Milling machine arbors with 7/24 tapers Part Il : Accessories 0 INTRODUCTION REFERENCES 2 During the prepatory work on ISO/R 839-1968, it was IsO 240, Milling cutters - Interchangeability dimensions for cutter arbors or cutter mandrels -- Metric series and found that it was impossible to unify milling machine arbors and their accessories in a manner which would be inch series. satisfactory to countries using the metric system and to ISO/R 272, Hexagon bolts and nuts - Widths across flats, those using the inch system. The isO Recommendation heights of heads,thicknesses of nuts -Metric series. therefore standardized two completely distinct series of accessories. There was thus no interchangeability between ISO 297, 7/24 tapers for tool shanks. these two series, based respectively on the metric and the so 839/1, Milling machine arbors with 7/24 tapers inch series of IS0 240. Part I : Dimensions. This International Standard retains metric series only, this series being regarded as the only one recommended for the future. Nevertheless, the inch series is given in an annex. CHOICE OF DIMENSIONS 3 The dimensions retained are those corresponding to the most commonly used diameters of milling machine arbors, i.e. the values of IS0 240 from 16 to 100 mm (omitting 19 mm and 70 mm). 1 SCOPE AND FIELD OF APPLICATION lengths I greater than 160 mm, as shorter arbors are usually This International Standard specifies the recommended intended for work which does not entail mounting on the manufacturing dimensions for milling machine accessories : machine with a steady (working in air) or, as a resuft, the spacing collars, bearing collars and clamping nuts. use of a bearing collar. Milling machine arbors with 7/24 tapers are specified NOTE -- This International Standard will be supplemented further in 1SO 839/l. by more precise specifications regarding tolerances. Copyright International Organization for Standardization 1 teworkingpemitedwithoutlicensefrom Not for Resale