BS-1981 Complete Document History
Specification for unified machine screws and machine screw nuts

Complete Current Edition:
   1991 EDITION - SPECIFICATION FOR UNIFIED MACHINE SCREWS and MACHINE SCREW NUT - Aug. 30, 1991
   AMD 7485 - AMENDMENT 1 FOR 1991 EDITION - Jan. 15, 1993

Obsolete Revision Information:
   1972 EDITION - OBSOLETE EDITION - Jan. 1, 1972