SOUTH AFRICAN NATIONAL STANDARD

Transcription

1 ISBN Edition 1 and nat. amdt 1 ISO 2904:1977 Edition 1 Any reference to SABS is deemed to be a reference to this standard (Government Notice No of 8 November 2002) SOUTH AFRIAN NATIONAL STANDARD Fasteners Part 2: Screw Section 17: ISO metric screw Basic dimensions This national standard is the identical implementation of ISO 2904:1977, and is adopted with the permission of the International Organization for ization. Published by SABS s Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001 Tel: Fax: SABS

2 Edition 1 and nat. amdt 1 ISO 2904:1977 Edition 1 Table of changes hange No. Date Scope Nat. amdt Amended to change the designation of SABS standards to SANS standards with no technical changes. National foreword This South African standard was approved by National ommittee SABS T 002, Screw and fasteners, in accordance with procedures of the SABS s Division, in compliance with annex 3 of the WTO/TBT agreement. This document is technically identical to SABS :1996. Reaffirmed and reprinted in August This document will be reviewed every five years and be reaffirmed, amended, revised or withdrawn. SABS

3 STANDARD ORGANIZATION FOR STANDARDIZATION l MEXAYHAPOAHAfi ISO metric Filetages m6triques trap6zoidaux OPrAHM3AUMR no TAHAAPTW3A~~W.ORGANISATION E DE NORMALISATION screw Basic dimensions ISO Dimensions de base First edition orrected and reprinted Ref. No. ISO (E) UD Descriptors : screw,, specifications, profiles, dimensions, s, thread pitch. Price based on 6 pages

4 fsr ization) is a wsrldwide federation ISO (the International Organization sf national standards institutes (ISO member bedies). The work of deveioping ternatisnal s is carried out through ISO technical csrmnittees~ Every ember body interested in a subject fcir which a technicaf committee has been set up has the right to be represented on that committee International organizations, governmental and nongowernmental, in Oiaissn vvith IIS d also take part in the work. Draft International s to the member bodies for s by the 6SO ouneil. adspted approval by the technical csmmittees are eireulated before their acceptance as %nternatiora %nternational fso 2904 was developed by Technical ommittee BSOJB 1, S~WV threacds, and was circulated to the rnember bsdies in June lt has been approved by the member Austria Belgium Brazil Kanada Denmark Finland France Germany bedies af the follswing Romania South Africa, Spain Sweden Switzerfand U.S.&. csuntries ex pressed Japan U.S.S.R. 0 6nkernational Printed Organizatisn in Switzerland for kation, 1977 : No rvasay Poland Hungary India Ireland My Korea, Rep. of Mexico Netherlands New Zealand The mem ber bod ies sf the following docurment on tcchnica Egr ound s : disapprowai Rep. of of the

5 ISO STANDARD ISO metric screw Basic dimensions 1 SOPE AND FIELD OF APPLIATION Da=d+2a This International for ISO metric ISO d3 =d2h, specifies the basic dimensions screw according to The values refer to the basic profiles 2 according to ISO REFERENES dz = D, =d2z=d0,5p ß, max. = 0,5 a, ß, max. = a, ISO metric screw Basic General ac = 4 clearance D* = 3 ALULATION d The values given in this International calculated from the following formulae = 0,5 P H4=H, h3 =H, z ia ta have been pitch = major dz = d, pitch = minor for for external external for external = 0,5 P + a, Hl = height of the overlapping = 0,5 P + a, Ha= height of internal h3 = height of external P = pitch = 0,25 P = H,/2 D, =d2h,=dp : on the crest = major D, = minor Hl where ISO 2901, /SO metric screw pro file and maximum material pro files. ISO 2902, plan. (E) : nominal