Acme threads have a 29° thread angle, which is easier to machine than square threads. … Acme threads are generally also stronger than square threads due to their trapezoidal thread profile, which provides greater load-bearing capabilities
What is an Acme Thread
Acme threaded rods and nuts. Calculation can be done for tolerance classes of 2G, 3G and 4G. Tolerance class 2G is the preferred class but if less play and backlash is needed, 3G or 4G can be selected. Angle of thread of general purpose Acme thread is 29°. The thread height is half of the thread pitch as mentioned above.
Acme thread form is a trapezoidal screw thread profile used for lead screws (power screws). There are different types of Acme threads such as General purpose, Stub Acme screw and Centralizing. General purpose and Centralizing Acme threads are defined in the ASME/ANSI B1.5-1997 standard and Stub Acme screw thread is defined in the ASME/ANSI B1.8-1988 standard. The differences between these types are summarized in the “Definitions” section.