Unified inch screw threads ANSI ASME B1.1
Unified ANSI ASME B1.1 inch thread, profile angle 60°, thread profile UN and UNR. UNR only applies to male threads, the difference between UN and UNR threads is that a flat or rounded base is specified for UN threads, and only a rounded base is specified for UNR threads. The catalog contains thread types UN, UNC, UNF, UNEF.