Differences between metric, inch and American threads.

The measurement units of pitch are different.

– The pitch measurement unit for metric thread is millimeter.

– The pitch measurement unit for inch thread is inch.

– The pitch measurement unit for American thread is also inch.

Categories are different.

– Type of metric thread: Metric thread has common thread (thread angle 60°); Trapezoidal thread (thread angle 30°); Buttless thread (thread Angle 33°); Square teeth thread and so on.

– Type of inch thread: According to the shape divided cylinder, cone two kinds; According to the thread angle divided 55°, 60° two kinds. The 1/4, 1/2, and 1/8 refer to the thread diameter, the units are inches.

– Types of American threads: The profile of American threads (profile Angle 60°, depth of truncation H/8), different from Wyeth Threads (thread angle 55°, depth of truncation H/6).

The thread standards are different.

– Thread standard for metric threads: G is a 55° unsealed pipe thread, belonging to the Wyeth thread family, marked G for straight thread.

– Thread standard of inch thread: PT is the abbreviation of Pipe Thread, is 55° seal tapered pipe thread, belongs to the Wyeth Thread family, mostly used in Europe and the Commonwealth countries. Commonly used in water and gas pipe industry, the taper is 1:16.

– Thread standard for American thread: NPT is the abbreviation for National (American) Pipe Thread. It belongs to the American standard of 60° taper screw thread, used in North America.