Acme threads are characterized in part by short thread height and 14.5° flank angles. Altogether, the software supports five related profiles: General Purpose Acme, Centralizing Acme, Stub Acme, Stub Acme Modified Form 1, and Stub Acme Modified Form 2. All profiles and tolerance classes have allowances for both external and internal threads.

Gage References : For all profiles, see the product references, except :

• For GO Setting Rings,see ASME B1.5-1997.
• For NOT GO Setting Rings,see ANSI/ASME B1.2-1983.
• The Stub Acme standard (ASME/ANSI B1.8-1988) does not specify truncated major diameters for setting plugs.

Note on using this software : Multi-Start Threads

The software has an option to use Nonmandatory Appendix B of ASME 1.5-1997. Otherwise, this software does not apply Appendix B, so dimensions are calculated the same as for single-start threads.

Working Thread Rings are used to gage external product threads. The "GO" ring should assemble with the product it is gaging, whereas the "NOT GO" ring should not. Generally, the minimum major diameter is specified, without a tolerance.

Working Thread Plugs are used to gage internal product threads. The "GO" plug should assemble with the product it is gaging, whereas the "NOT GO" plug should not. Generally, the maximum minor diameter is specified, without a tolerance.

Setting Rings are used to set indicating gages for internal product threads. GO rings are used to set gages to the maximum material size, NOT GO for the minimum material size. Generally, the minimum major diameter is specified, without a tolerance.

Setting Plugs are used to set indicating gages for external product threads, in addition to adjustable working ring gages. GO plugs are used to set gages to the maximum material size, NOT GO for the minimum material size. Generally, the maximum minor diameter is specified, without a tolerance.