BS 1580 – Specification for Unified screw threads. Diameters 3/16 in and larger

Unified coarse thread series UNC 3/16 in to 4 in diameter; Unified fine thread series UNF 3/16 in to 1½ in; Unified extra fine thread series UNEF 3/16 in to 1 11/16 in. Standard constant pitch series for a graduated system of diameter/pitch combinations. Basic and design forms. Tables of basic dimensions, limits and tolerances for all diameter/pitch combinations in UNC, UNF, UNEF and standard constant pitch series given for the three classes of internal and external threads. Bases of tolerances for Unified screw threads; five sizes below 3/16 in diameter for attachment purposes and for general use in aircraft appended. Evolved through international discussions between UK, Canada, USA. In accord with corresponding sections of American standard ASA B1.1-1960.

Cross References:
BS 84
BS 93
BS 768
BS 919:Part 1
BS 1750
BS 1768
BS 1769
BS 1981
BS 2470
BS 2708
BS 3139
BS 3382
BS 3580
BS 4084

Incorporates the following:
AMD 1345 published 15 January 1974
AMD 2782 published 15 March 1979