Form of thread defined. Tables: basic sizes, limits, tolerances for 'class' bolts , nuts; BS Whitworth range, 1/8 in to 6 in; BS Fine range, 2/16 in to 4 2/16 in (limits and tolerances up to 3 in only). Also a Selected Thread series more suitable than BS Pipe parallel series for extra fine pitch applications. Appendices: limits, tolerances for B.S .W. and B.S.F. truncated bolts and nuts; bases of tolerances and allowances, formulae; effects of pitch and angle errors, acceptability of error combination; form of Whitworth crests; limits and tolerances for (non-preferred) 'close class' nuts.

? British Standards Institution 2013

Amendment notes:
PD 5902 published 11 August 1966

BS 84:2007

AS B47-1958 - Equivalent