(22) Tandem Style ACME Tap Application Tandem Style Taps produce threads of from 10º to 30º included angle in a single pass without a leadscrew. The roughing section of the tap has a thread with a sharper angle which permits threads to be relieved more effectively and eliminates the wide, flat Acme crest. This results in free-cutting characteristics which makes greater stock removal possible. The last few threads on the roughing section act as a guide for the short finishing section, which corrects the angles and brings the thread to size.
(23) ACME Tap Application For Additional Special Tap Requirements Prices for Special Acme Taps having engagements longer than the standard 60º thread lengths, course pitches . exotic materials.. Ordering information requested for Special Single Acme Taps— A. Nominal Size. B. Threads per Inch. C. Single or multiple threads (Note—Indicate the number of threads and lead for multiple lead taps — Example: 1/2-12,1/6 lead double. D. Blind or Through Hole (Note—for blind holes, give clearance beyond the thread depth. For through holes, state whether tap will be passed through or backed out.) E. Depth of Hole, Bore before Tapping and Wall Thickness of part, if less than 1/2" F. ...
