In the pipe thread designation '2 1/2-8', what does the '8' represent?

In the pipe thread designation '2 1/2-8', what does the '8' represent?

• A. 8 Threads Per Inch
• B. Outer Diameter In Inches
• C. Pipe Grade
• D. Thread Length In Inches

Answer: (A)

In pipe thread designations, the number after the dash indicates the thread pitch: how many threads appear in one inch of the threaded portion. So for a designation like 2 1/2-8, the first part (2 1/2) is the nominal pipe size, and the trailing 8 means there are 8 threads per inch along the thread. This is the thread count used to match fittings with the same pitch. It’s not the outer diameter, the thread length, or any pipe grade.

In pipe thread designations, the number after the dash indicates the thread pitch: how many threads appear in one inch of the threaded portion. So for a designation like 2 1/2-8, the first part (2 1/2) is the nominal pipe size, and the trailing 8 means there are 8 threads per inch along the thread. This is the thread count used to match fittings with the same pitch. It’s not the outer diameter, the thread length, or any pipe grade.