Van Keuren NPT Tapered Pipe Thread Plug Gage Assemblies These Thread Plug Gages allow you to check tapered and straight internal pipe threads. Perfect for inspecting standard pipe and pipe fittings.These Van Keuren Pipe Thread Plug Gages are made to precise Class X tolerances per ASME B1.20.1 and include a Certificate of Accuracy. Each Thread Plug Gage includes Handle - light blue in color.Select Specific Thread Size from Pull Down Menu. Need a Certificate of Calibration? These Thread Plug Gages are shipped "off-the-shelf" without a Certificate of Calibration. If you need a Certificate of Calibration, you can order the following Calibration Service with the Gage... Standard Calibration Includes a "long form" Certificate of Calibration that is traceable to NIST. A GO/NOGO Thread Plug Gage will include 2 Certificates of Calibration. 1 for the GO member 1 for the NOGO member