SPI 34-442-4 2-11-1/2 NPT Class L-1 Pipe Thread Plug Gage

The SPI 34-442-4 is a new, single-end tapered pipe thread plug gage conforming to ANSI/ASME B1.20.1 for 2-inch NPT (National Pipe Taper) threads at 11-1/2 threads per inch, Class L-1 (working gauge) tolerance. The plug gage uses a truncated taper plug design with a hardened and ground alloy steel thread form, calibrated to check the pitch diameter at the L-1 hand-engagement plane to verify that a female NPT-threaded component is within the correct tolerance range for a sealing pipe joint. Markings visible on the handle shank read "2-11-1/2 NPT / L1 / PRN / 6658," where PRN is the SPI lot/calibration code and 6658 is the serial/inspection number, confirming traceability to NIST-traceable standards. Handle size 5 is the standard heavy-duty handle used for 2-inch NPT class gages, providing sufficient grip mass for accurate hand-engagement torque. This gage is suited for production inspection of 2-in NPT female threaded fittings, valves, pipe flanges, and machined housings where a leak-free taper thread seal is required.

Product Specifications