X-Over 4-1/2" EUE BOX X 5-1/2" LH-4-STUB ACME PIN
ACME female thread is actually a trapezoidal thread, which is closer to the metric trapezoidal thread. However,ACME female thread has low teeth, while metric trapezoidal thread does not have low teeth.
The major diameter of general purpose ACME thread and short tooth ACME thread is the same, with the main difference being the tooth height. From the above figure, we can see that the tooth height for general use is H=0.5P, while the short tooth is H=0.3P. For example, thread representation: general purpose ACME thread: 3/8-12 ACME-2G; Short tooth ACME-2G female thread: 3/8-12 STUB ACME-2G. The latter 2G is the accuracy level.