This British Standard specifies limits of sizes, and tolerances, for single
start parallel screw threads of Whitworth form, for general engineering
use. It is not applicable to threads for threaded pipe joints, screw
threads associated with interference fits, such as those on the “metal
ends” of studs and in the corresponding tapped holes, or to screw
threads which are to be subjected to high temperatures.
This standard specifies the following thread series:
a) a coarse thread series, the British Standard Whitworth (B.S.W.)
series, with nominal diameters in the range in to 6 in.
b) a fine thread series, the British Standard fine (B.S.F.) series, with
nominal diameters in the range in to 4 in.
NOTE The tables of limits and tolerances for the B.S.F. series extend
up to the 3 in size only, since nominal sizes above 3 in are rarely used.
c) a supplementary selected thread (WHIT. S.) series with nominal
diameters from in to 7 in.
d) a truncated Whitworth form series (specified in Annex A).
This British Standard specifies limits of sizes, and tolerances, of
uncoated threads and also for metal coated threads (including threads
coated with nickel, tin or zinc) with a thickness of coating of the order
of 0.000 2 in. It is not applicable to heavily coated threads (i.e. threads
with a coating thickness above 0.000 35 in).
NOTE Supplementary information is given in Annex B, Annex C and
Annex D.
BS 84:2007 Referenced Document
BS 919-2 Screw gauge limits and tolerances – Part 2 : Specification for gauges for screw threads of Whitworth and B.A. forms
BS 84:2007 history
2007BS 84:2007 Parallel screw threads of Whitworth form – Requirements
1956BS 84:1956 Specification for parallel screw threads of Whitworth form