scope:

General and Historical

1 When formulated, prior to 1895, Acme screw threads were intended to replace square threads and a variety of threads of other forms used chiefly for the purpose of producing traversing motions on machines, tools, etc. Acme screw threads are now extensively used for a variety _of purposes. This standard is a revision of ASA Bl.S-1952 and provides for two general applications of Acme threads, namely, general purpose and centralizing.

The limits and tolerances in this standard relate to single start Acme threads, and may be used, if considered suitable, for multi-start Acme threads. The latter threads are used to provide fast relative traversing motion when this is necessary.