The JBO Thread Plug Gauge is a precision inspection tool designed to verify metric fine-threaded holes. Built for machinists, quality inspectors, and assembly specialists, it provides fast, reliable go/no-go checks to ensure components thread together cleanly and consistently.

With a compact, rugged design and hardened steel construction, this gauge stands up to daily use in workshops, manufacturing floors, and job sites where accurate thread tolerances matter.

• Go/No-Go design for fast, reliable checks on right-handed metric threads: Quickly confirm that a threaded hole meets the minimum engagement (Go) and will not accept an oversized insertion (No-Go), speeding up inspections and reducing guesswork.
• Specifically matched to M39 x 2 fine threads (4H): Precisely calibrated for the metric fine pitch M39 x 2 with 4H tolerance, delivering consistent results across parts and production runs.
• Hardened steel construction for long service life: Built to endure frequent use, resist wear, and provide dependable performance in busy shop environments.

Using this gauge helps you streamline quality control, minimize rework, and ensure that thread assemblies fit smoothly every time. Its clear go/no-go feedback supports quicker, more confident decisions on the shop floor, improving workflow, reducing downtime, and enhancing overall production reliability.