AS B202-1962

Based on the American Acme Screw Thread Standard ANSI B1.5 1952 This Standard defines the Acme form of thread and gives complete tables of basic sizes, limits and tolerances for a Standard Series of single-start Acme screw threads in the range n to 5 in. diameter. This Standard Series is in agreement with that given in ANSI B1.5 except for the pitches associated with diameters 3/8 in., 7/16 in., 1 in., 1-1/8 in., and 1¼ in. The three classes of fit 2G, 3G, and 4G in the US Standard are given and an additional finer class 5G is also provided.

This British Standard recommends a Standard Series of diameters and associated pitches for General Purpose Acme form screw threads, for the nominal size range 1/4in. to 5 in. and specifies the limiting dimensions, tolerances and allowances for four classes of thread.Information is also provided whereby the limiting dimensions for any other screw thread of Acme form may be determined, but the use of these special diameter/pitch combinations should be avoided wherever possible.Recommendations are given in Section Two regarding the types and dimensions of gauges to be used.

Reconfirmed 1984, 1987