GENERAL

This standard for Metric Flat 90^o countersunk Head 6-Lobed Socket Tapping Screws of thread forming Types AB and B and thread cutting Types BF and BT conforms in all essentials, except driving provisions, with the American National Standard covering metric tapping screws. . It should be noted that the head diameter and head height limits specified herein differ to varying extents from those documented in prior issues. In general, however, thread forming types of screws made in conformance with this standard are considered to be functionally interchangeable with parts produced to the latest ISO Standard for recessed pan head tapping screws. Also, for the most part, the Type 1A cross recess configuration will serve to identify these screws as being metric