2G is the most commonly used class. If you wish to have lesser backlash in ACME threads, we can use 3G & 4G class. Also, the height of ACME threads is 0.5p and the height of Stub ACME threads is 0.3p.

GO Gauge: When the GO gauge enters and passes the complete length of the work piece thread under the condition that it is screwed by hand and does not use excessive force.

NOT GO Gauge: When the NOT GO gauge do not enter the component by more than two turns of the thread from both ends under the condition that it is screwed by hand and does not use excessive force