PTF SAE Short Projection Straight Pipe Taps
PTF-SAE Short internal threads are used in couplings/fittings when a shorter length of engagement is desired. Dryseal SAE taps produce a thread that is one pitch (thread) shorter at the large end of the coupling.
The SAE Short Internal Taper Pipe Thread is intended for assembly with NPTF external pipe thread. The SAE straight dryseal internal thread will also assemble with the NPTF external thread. The term "short" applies to the projection of the tap through the standard L-! ring thread gage.