The JBO Thread Plug Gauge is a precision inspection tool designed for left-hand metric fine threads. Specifically sized for M40 x 1.5 and built to the 6H class, this Go/No-Go gauge makes it quick and easy to verify internal thread holes with confidence. Its dual-function design supports fast checks during setup, inspection, and assembly, helping keep production moving smoothly.

• Go/No-Go design for fast, reliable inspections: Quickly determine if a threaded hole meets tolerance—Go for a clean, full-depth fit and No-Go for a binding clearance—reducing guesswork and speeding up quality checks.
• Hardened steel construction for long-lasting durability: Built to endure daily workshop use, resist wear and corrosion, and maintain accurate readings through hundreds of inspections without re-calibration.
• Precise metric fine-thread compatibility (M40 x 1.5, 6H): Engineered to exact metric fine-thread standards, including 6H tolerance, ensuring consistent, reliable checks for critical assemblies in engineering and manufacturing environments.

Designed to improve accuracy and efficiency in quality control, the JBO Thread Plug Gauge helps you confirm correct thread engagement with minimal downtime. By delivering quick, repeatable checks for left-hand Metric fine threads, it supports tighter tolerances, faster part clearance, and more dependable assembly outcomes across jobs and teams.