NATIONAL FOREWORD

This Indian Standard (First Revision) which is identical with ISO 6848 : 2015 ‘Arc welding and cutting — Nonconsumable tungsten electrodes — Classification’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Welding General and its Applications Sectional Committee and approval of the Metallurgical Engineering Division Council.

This standard was originally published as IS 13007 : 1991 ‘Tungsten electrodes for inert gas shielded arc welding and for plasma cutting and welding — Specification’. The Committee has now decided to adopt this standard under dual numbering system to make pace with the latest developments that have taken place at International level. The first revision of this standard has been undertaken to align it with the latest version of ISO 6848 : 2015.

Tungsten electrodes are used in a variety of welding and allied processes, including tungsten inert gas welding, plasma arc welding and cutting, plasma spraying, and atomic hydrogen welding. In contrast to most other welding electrodes, tungsten electrodes are not intended to become part of the weld deposit. Nevertheless, the chemical composition of a tungsten electrode has an important effect on its range of usage in welding and allied processes. Therefore, tungsten electrodes are classified according to their chemical composition.

The text of ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain terminologies and 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.