BS 84:2007

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 coarse thread series, the British Standard Whitworth (B.S.W.) series, with nominal diameters in the range in to 6 in. a fine thread series, the British Standard fine (B.S.F.) series, with nominal diameters in the range in to 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. a supplementary selected thread (WHIT. S.) series with nominal diameters from in to 7 in. a truncated Whitworth form series (specified in AnnexA). 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 0.0002 in. It is not applicable to heavily coated threads (i.e. threads with a coating thickness above 0.00035 in). NOTE Supplementary information is given in AnnexB, AnnexC and AnnexD.