IS 4218 : Part 2 : 2001 /ISO 261 : 1998 ISO General Purpose Metric Screw Threads - Part 2 : General Plan

NATIONAL FOREWORD

This Indian Standard ( Part 2 ) ( Second Revision ) which is identical with ISO 261 :1998 ‘ISO general purpose metric screw threads - General plan’ issued by the International Organization for Standardization ( ISO ) was adopted by the Bureau of Indian Standards on the recommendation of the Engineering Standards Sectional Committee and approval of the Basic and Production Engineering Division Council.

This standard was originally issued in 1967 and subsequently revised in 1976. The first revision was based on ISO 261:1973. This second revision has been issued by adopting ISO 261:1998.

This Committee, responsible for preparation of Indian Standards on Screw Threads, decided to revise all tne six parts of IS 4218 in the following manner:

a) The revised IS 4218 to be published in four parts, that is ( Parts 1 to 4 ) adopting ISO 68-1:1998, ISO 261:1998, ISO 724:1993 and ISO 262:1998 respectively covering the various requirements of ISO general purpose metric screw threads except tolerances;

b) For tolerances on ISO general purpose metric sqrew threads a new standard, that is, IS 14962 to be published in five parts, that is ( Parts 1 to 5 ) by adopting ISO 965 ( Part 1 ) :1998, ISO 965 ( Part 2 ) : 1998, ISO 965 ( Part 3 ) : 1998, ISO 965 ( Part 4 ) : 1998 and ISO 965 ( Part 5 ) :1998 respectively; and

c) After the publication of above standards IS 4218 ( Part 5 ) :1979 and IS 4218 ( Part 6 ) :1978 stand withdrawn.

The text of ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. In the adopted standard, certain conventions are not identical to those used in Indian Standards. Attention is especially drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practice is to use a full point (.) as the decimal marker.