Thread Plug Gauge Supplier. A thread plug gage is used to check acceptance of a “nut” , (an internally threaded part). For small threaded parts, the gage will be double ended, with one end carrying the GO gage and the other end, the NOGO. ... A thread plug gage is designed to check the pitch diameter (to the given pitch / Threads per inch). We are dealing with all type of industrial gauges of proven quality. Please contact for more details.