Product Details:

APL offers a complete line of standard and special General Purpose Acme Thread Gauges per ASME B1.5 – 1997. Acme Thread Gages are used to gage internal and external threaded product. Thread size combinations including multiple start threads, centralizing threads, Stub Acme, Centralized Stub Acme, 60 degree Stub and diameters over 5.0 inches can be priced on request. Acme General Purpose threads have 3 classes of fit – 2G, 3G, and 4G.

General Purpose Threads class 2G, 3G, and 4G are designed with clearance on all diameter which enables free movement. General Purpose These threads are ideal for assemblies where the internal thread is rigidly fixed and the external thread moves perpendicular to its axis. It is recommended that threads of the same class should be assembled together. Class 2G is the most popular thread class of fit. Class 3G and 4G should be used if less backlash is required.

Other types of threads are Stub Acme and Centralizing Stub Acme.
All Acme threads have a 29 degree included angle.