BS 2827 – Specification for machine screw nuts, pressed type (B.A. and Whitworth form threads)
Gives general dimensions and screw thread limits for square and hexagon machine screw nuts of the pressed type with B.A. threads, B.S.W., B.S.F. or other Whitworth form threads. The size ranges covered are from 6 B.A. to 0 B.A. inclusive, and from ^3/$d3$d2 in-48 Whitworth to 3/8 in B.S.W. and B.S.F.
