NATIONAL FOREWORD

This Indian Standard (Second Revision) which is identical with ISO 3315 : 2011‘Assembly tools for screws and nuts — Driving parts for hand-operated square drive socket wrenches — Dimensions and tests’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Hand Tools Sectional Committee and approval of the Production and General Engineering Division Council.

This standard was first published in 1976 and subsequently revised in 1991. This standard has been revised again to align it with the latest ISO 3315 : 2011 by adoption under dual numbering system.

In this revision several changes has been made in dimensions of speed brace, screw driver, nut spinner and offset handles along with introduction of new nominal sizes. Methods of torque test has been specified and endurance test for ratchet handles have been specified.

The Standard is published in two parts and the other part of the standard is as under:

Part 1 Technical supply conditions

The text of ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions are howevernot identical to those used in Indian Standards. 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.