The JBO Thread Plug Gauge is a precision tool designed for metric fine threads. It’s ideal for engineers, machinists, inspectors, and shop professionals who need quick, reliable verification of threaded holes. With its Go/No-Go design, you can confirm fitment in seconds, helping you move from setup to assembly with confidence.

Specifically tuned for left-hand M39 x 2 threads and 6H hole tolerances, this gauge makes it easy to verify whether a hole meets the exact spec required for mating components. Built for durable daily use, it remains accurate even after repeated insertions and removals.

• Go/No-Go Quick Check for Metric Fine Threads: The two ends clearly indicate pass or fail, allowing you to inspect holes in seconds and reduce assembly delays.
• Left-Hand Thread Compatibility: Designed to measure left-hand threads, preventing misreads and ensuring correct assembly across components.
• Hardened Steel Construction for Longevity: Durable, wear-resistant material stands up to daily shop use, preserving accuracy over time.

With the JBO Thread Plug Gauge, you streamline your threading workflow—from setup through quality control—so you can rely on consistent thread engagement, minimize rework, and speed up production without compromising accuracy. Its robust construction and precise go/no-go indications give you greater confidence on the shop floor.