JBO Plug Gauge - UNC (STI) Heli Coil Gauge - Right Hand - 2B - 5/8 x 11 - Calibrated (DAkkS Calibration)Helicoil gauges are manufactured and assessed in accordance with the relevant ANSI standards, specifically those defined by the American National Standards Institute ASME thread system. The JBO Plug Gauges UNC (STI) Wire Inserts are precision measuring tools designed specifically for UNC (Unified National Coarse) Screw Thread Inserts (STIs). These plug gauges play a critical role in ensuring accurate and reliable measurements of threaded inserts in