Shop Vermont Gage, GWS/North American and select Balax thread plug gages for inspecting internal threads. Choose GO and NO-GO members, inch or metric thread sizes, direction and class of fit. GO members verify the thread can accept the mating part; NO-GO members help identify out-of-tolerance threads. Use standard plug gages for finished tapped holes and STI plug gages only for screw thread insert holes. Select Florida Local Stock for live Suncoast quantities or shop more sizes online.