PTF

Also known as PTF – SAE Short, American Standard Taper Thread

 

NPTF

American Standard Taper Pipe Thread for Dryseal Pressure

 

NPT

Same as PTF except full thread length is lengthened by one thread on the small end

 

PTF - SPECIAL SHORT

One full thread has been shortened from the large end of the thread

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PTF - SPECIAL EXTRA SHORT

Two full threads have been shortened from the large end of the thread

 

NPSM

American National Standard Straight Pipe Thread for mechanical joints

 

NPSI

American National Dryseal Intermediate Internal Straight Pipe Thread

 

NPSF

American National Dryseal Fuel Internal Straight Pipe Thread