INSIZE Standard Thread Plug Gages GO / NO GO - 2B These Thread Gages allow you to inspect the pitch diameter and the functional thread for internal threaded products.All stock Thread Plug Gages are made to standard tolerances per ANSI / ASME B1.2 (Unified Inch Screw Threads).A Manufacturer Inspection Certificate is included with each gage. Each Thread Size includes a GO & and a NO GO thread.Select Specific Thread Size from Pull Down Menu.