IS 554 : 1999 /ISO 7-1 : 1994 Pipe Threads Where Pressure-Tight Joints are Made on the Threads - Dimensions, Tolerances and Designation

National Foreword

This Indian Standard (Fourth Revision) which is identical with ISO 7-l : 1994 �Pipe threads wherepressure-tight joints are made on the threads - Part 1 : Dimensions, tolerances and designation�,issued by the International Organization for Standardization (ISO) was adopted by the Bureau ofIndian Standards on the recommendation of the Engineering Standards Sectional Committee andapproval of the Light Mechanical Engineering Division Council.

This standard was originally issued in 1955 and subsequently revised in 1964 and 1985. The thirdrevision was harmonized with ISO Standard by adopting ISO 7-1 : 1982. This fourth revision has beentaken up to align it with the latest version of ISO 7-l which has been technically revised in 1994.

The text of ISO Standard has been approved as suitable for publication as an Indian Standard withoutdeviations. In the adopted standard certain conventions are not identical to those used in IndianStandards; attention is especially drawn to the following:

a) Wherever the words �International Standard� appear referring to this standard, they should beread as �Indian Standard�.

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

In this adopted standard, reference appears to one International Standards for which Indian Standardalso exists. The corresponding Indian Standard which is to be substituted in its place are listed belowalong with its degree of equivalence for the editions indicated: