BS 93:2008 PDF

Scope: This British Standard specifies limits of sizes, and tolerances, for single start parallel screw threads of British Association (B.A.) form. It is not applicable to screw threads associated with interference fits, such as those on the “metal ends” of studs and in the corresponding tapped holes. This British Standard specifies the following: a) basic sizes for B.A. threads, sizes 0 B.A. to 16 B.A.; b) limits of size, and tolerances, for close class and normal class external threads of sizes 0 B.A. to 10 B.A.; c) limits of size, and tolerances, for normal class external threads of sizes 11 B.A. to 16 B.A.; d) limits of size, and tolerances, for a single class of internal threads of sizes 0 B.A. to 16 B.A.

BS 93:2008 Referenced Document

BS 919-2 Screw gauge limits and tolerances – Part 2 : Specification for gauges for screw threads of Whitworth and B.A. forms

2008 BS 93:2008 British Association (B.A.) screw threads - Requirements
1951 BS 93:1951 Specification for British Association (B.A.) screw threads with tolerances for sizes 0 B.A. to 16 B.A