The Original Thread Checker

U.S. Patent No. 7877882

The Original Thread Checker is an accurate and easy-to-use thread verifier for both nuts and bolts.

Conveniently assembled onto a wire loop, it is especially well suited for distinguishing between similar inch and metric threads.


  • Each size has a nut and bolt checker on the same gauge
  • Thread sizes are permanently stamped onto each gauge
  • Inch gauges are clear zinc plated, metric gauges are black oxide
  • Wire cable with loop for convenient hanging