This British Standard specifies limits of sizes, and tolerances, for single start parallel screw threads of Whitworth form, for general engineering use.
While Whitworth threads have remained unchanged since the last revision of BS 84 in 1956, the present revision of the Standard has been undertaken on the basis that Whitworth threads will undoubtedly continue to be used for many years, especially on replacements or spare parts.
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 1/8 in to 6 in.
b) a fine thread series, the British Standard fine (B.S.F.) series, with nominal diameters in the range 3/16 in to 4 1/4 in.
c) a supplementary selected thread (WHIT. S.) series with nominal diameters from 1/4 in to 7 in.
d) a truncated Whitworth form series.
BS 84:2007 contains:
- Normative reference
- Terms, definitions and symbols
- Profile of Whitworth screw thread
- Tolerance classes of external and internal thread
- Limits of sizes, and tolerances, for uncoated B.S.W. and B.S.F. threads
- Limits of sizes, and tolerances, for B.S.W. and B.S.F. coated threads
- Stainless steel external threads
- Selected thread series
- Designation of screw threads of Whitworth form
- Gauges
This British Standard is intended for use with BS 919-2, which specifies the corresponding screw gauges.
BS 84:2007 replaces BS 84:1956, which is withdrawn.