Revised Standard from Last Update.

NATIONAL FOREWORD

This Indian Standard (First Revision) which is identical with ISO 4759-3 : 2016 ‘Tolerances for fasteners — Part 3: Washers for bolts, screws and nuts — Product grades A, C and F’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on recommendation of the General Engineering and Fasteners Standards Sectional Committee and approval of the Production and General Engineering Division Council.

The original version of this standard IS 15274 : 2003 was based on ISO 4759-3 : 2000 issued by ISO. This first revision has been taken up to align with the latest version of ISO 4759-3 published in 2016. This standard was originally published in 2003 which was based on ISO 4759-3 : 2000. The first revision of this standard has been undertaken to align it with the latest version of ISO 4759-3 : 2016.

The major changes in this revision are as follows:

a) the scope has been amended;

b) the normative references have been updated;

c) a new Clause 3 "Symbols and abbreviated terms" has been added;

d) new product grade F has been included (F for Fine tolerances);

e) tolerances for chamfers have been included;

f) in Table A.1 tolerances for standard tolerance grades IT11 and IT14 have been included and IT16 has been deleted;

g) in Tables A.2 and A.3 limit deviations for tolerance classes h13 and H12 respectively have been included;

h) the bibliography has been updated; and

j) this part of ISO 4759 has been editorially revised.