The JBO Plug Gauge - Metric Fine (STI) Heli Coil Gauge is a precision measuring tool designed to verify metric screw thread inserts (STIs). It's built for engineers, machinists, quality teams, and shop-floor technicians who need fast, reliable checks to confirm inserts meet exact size and tolerance for consistent assembly.

This right-hand gauge is sized M12 x 1.25 with a 6H tolerance and is calibrated to DAkkS standards, ensuring traceable, auditable measurements. It follows ANSI/ASME thread guidelines, delivering dependable go/no-go results that support quality systems across manufacturing, automotive, and aerospace applications.

• DAkkS-traceable calibration: Ensures traceable, auditable measurements that satisfy QA documentation and audits, providing confidence in every check.
• Right-hand, metric STI compatibility: Precisely sized for M12 x 1.25 inserts with 6H tolerance, enabling fast, accurate pass/fail checks in right-hand threading contexts.
• Durable, ergonomic construction: Knurled, corrosion-resistant body and robust end features deliver long service life and a secure grip in busy workshop environments.

Using the JBO plug gauge on incoming parts or in-process checks reduces rework by giving you quick, reliable confirmation that inserts meet spec. The calibrated accuracy supports consistent performance across batches, streamlines quality reporting, and helps you maintain tight tolerances without slowing down production.