The JBO Thread Plug Gauge is a precision inspection tool designed for metric fine threads. It’s ideal for machinists, engineers, quality-control teams, and workshop professionals who need fast, reliable checks that keep assemblies on spec. Engineered for M4 x 0.35 with 6H tolerance and right-hand threads, this gauge helps you confirm hole sizes quickly without guesswork.

With a Go/No-Go design, you can instantly verify whether a threaded hole accepts the plug to the correct tolerance, speeding up QC cycles and reducing rework. The instrument features hardened steel construction for enduring performance, resisting wear through repeated use in demanding shop environments.

• Go/No-Go quick verification: Instantly determine whether a hole meets the required metric fine thread tolerance, speeding up inspections and reducing guesswork during assembly.
• Hardened steel for long life: Built to withstand frequent use, resisting wear and maintaining measurement accuracy in busy workshop environments.
• Precise metric compatibility (M4 x 0.35, 6H, right-hand): Designed specifically for metric fine threads, ensuring reliable fits for corresponding parts and simplifying quality control with standard thread geometry.

This plug gauge helps you streamline quality control, shorten setup times, and ensure consistent threaded connections across assemblies. By delivering clear go/no-go results with durable performance, it supports faster production cycles, fewer reworks, and improved overall reliability in your machining or manufacturing workflow.