21. Taps for Pipe Threads 2. American Pipe Thread Taps Description of products American standard pipe thread has various types. We show their symbols and engagement of threads as follows. ■Pair groups of external thread and internal thread. Standard Symbol Internal Thread Mating Thread External Thread Mating Thread American Standard Taper Pipe Thread for General Use American Standard Straight Pipe Thread in Pipe Couplings American Standard Taper Pipe Threads for Railing Pipe Threads, General Purpose Joints (ANSI/ASME B1.20.1) American Standard Straight Pipe Thread for Free- Fitting Mechanical Joints for Fixtures American Standard Straight Pipe Thread for Loose-Fitting Mechanical Joints with Locknuts American Standard Straight Pipe Threads for Loose- Fitting Mechanical Joints for Hose Couplings Dryseal American Standard Taper Pipe Thread Dryseal SAE Short Taper Pipe Thread Dryseal Pipe Threads (ANSI B1.20.3) Dryseal American Standard Fuel Internal Straight Pipe Thread Dryseal American Standard Intermediate Internal Straight Pipe Thread Note : These symbols correspond to the name of American pipe thread. These threads are (1) Thread angle is 60˚ (2) Taper of Taper Thread is 3/4" per foot. (3) Fundamental height of triangle : H=Height of triangle thread profile H=0.866025P (4) The difference between American Standard Pipe Thread for general use and Dryseal American Standard Pipe ・Crests and roots truncation of thread is different. ・The length of engagement for pipe thread is different by types. ・With regard to standard, Dryseal American Standard Pipe Thread is available in right hand. In accordance with ANSI B 94.9, 4 types of pipe thread are specified in American Pipe Thread Standard. Please refer to next page about the relation between taps and threads and about thread tolerance. Information Technical Technical-60 831