NPT teeth, PT teeth, PF teeth, pipe thread difference
A tooth, NPT
The NPT is the American standard taper pipe thread for general use.
Where N said National (American) National standards in the United States, said P PIPE tube, T said TAPER conical, tooth type Angle 60 °. This type of pipe thread is commonly used in North America or is often seen in the use of ANSI specifications. NPT teeth must be used in ANSI specifications.
Second, the PT teeth
PT tooth for imperial tapered thread, tooth type Angle is 55 °, the most commonly used in sealing. It is commonly used in European and commonwealth countries. In Taiwan and Japan, the JIS standard also adopts the British standard. China also USES the British screw tooth, which belongs to the hui screw family. GB/ t7306-2000 is available for national standards.
English pipe thread is a fine thread, which can guarantee the strength of the tapping part. Because the tooth depth of the thick thread is large, the strength of the pipe with the outside diameter of the cut thread will be seriously reduced.
PT teeth must be used in the JIS specification.