Revised Standard from Last Update.

NATIONAL FOREWORD

This Indian Standard (Part 2) (First Revision) which is identical with ISO 6621-2 : 2020 ‘Internal combustion engines — Piston rings — Part 2: Inspection measuring principles’ issued by International Organization for Standardization (ISO), was adopted by the Bureau of Indian Standards on the recommendations of the Automotive Prime Movers, Transmission Systems and Internal Combustion Engines Sectional Committee and approval of the Transport Engineering Division Council.

This subject was first covered in IS 12022 : 1987 ‘Method of testing of quality characteristics of piston rings’. The standard was withdrawn subsequent to publication of IS/ISO 6621-2 : 2003 ‘Internal combustion engines — Piston rings — Part 2: Inspection measuring principles’. This first revision of the Indian Standard has been undertaken to harmonize it with ISO 6621-2 : 2020. The main changes from the previous edition are as follows:

a) Oil ring diameter range for ring widths 3.0 mm and 3.5 mm increased up to 160 mm.

The text of the ISO standard has been proposed to be approved as suitable for publication as Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian Standard. Attention is particularly 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 point (.) as the decimal marker.

In this adopted standard, reference appears to certain International Standards for which Indian Standards also exist. The corresponding Indian Standards, which are to be substituted in their respective places, are listed below along with their degree of equivalence for the editions indicated: