The JBO Thread Plug Gauge is a precision inspection tool for metric coarse threads. With left-hand Go/No-Go operation and an M39 x 4 hole size, it’s ideal for quality checks, assembly verification, and maintenance. Crafted from hardened steel, it stands up to daily shop use and maintains accuracy over time.

• Go/No-Go accuracy for fast inspection: Quickly verify whether a threaded hole meets spec, delivering clear pass/fail results to speed up QC and reduce rework.
• Rugged hardened steel construction: Built to endure repetitive use in busy environments, resisting wear and corrosion to preserve long-term accuracy.
• Precise sizing for M39 x 4 left-hand coarse threads (6H): Specifically matched to your application, ensuring reliable checks and consistent fitment with minimal guesswork.

Using the JBO Thread Plug Gauge simplifies quality control, accelerates setup, and improves consistency across parts and operators. Its durable build and precise M39 x 4 left-hand threading check reduce downtime and rework, helping you move parts through production with confidence and dependable results.