UN STI Plug Gages
Steel Thread Insert (STI) thread gages inspect the pitch diameter and the functional thread form for internal threads that will have a steel thread insert installed. The STI thread gages listed are made to Class X tolerances per ANSI B1.2 (Unified inch screw threads). All thread gages are supplied with a Certificate of Accuracy. STI plug gages are stocked in 2B & 3B (inch) classes of fit. Stocked STI plugs are chrome plated. All thread gages are marked with nominal size, threads per inch (inch), class of fit, and pitch diameters.