This procedure is recommended for the conversion of U.S. to metric dimensions in the preparation of drawings@ specifications@ and published data for color and monochrome television picture tubes and their component parts. Consideration has been given to both the ASTM (American Society@ for Testing and Materials) Metric Practice Guide and the IEC (International Electrotechnical Commission) Publication 191-1. This practice utilizes the procedures of both Standards which are most applicable to the specific requirements of color and monochrome television picture tubes.