The JBO Thread Plug Gauge is a precision tool designed for inspecting metric fine threads. Its Go/No-Go design lets you quickly verify threaded holes, helping ensure parts fit together correctly and consistently.

This Left Hand version is sized for M20 x 1 threads with 6H tolerance, and is built from hardened steel for long-lasting performance in demanding shop environments. The rugged, knurled body also provides a secure grip for easy handling during gauging.

• Go/No-Go design for quick inspection: Quickly determine whether a threaded hole meets specification, reducing inspection time and minimizing guesswork during assembly.
• Hardened steel construction for durability: Built to resist wear and stand up to daily use in busy workshops, delivering reliable performance over time.
• Metric fine-thread compatibility (M20 x 1, left-hand, 6H): Precisely matched to the target thread type, enabling consistent, repeatable checks and fewer misfits in production.

This gauge helps streamline quality checks and assembly, improving workflow accuracy and reducing downtime. By providing clear Go/No-Go feedback for the intended M20 x 1 left-hand threads, it supports faster setup, fewer rework cycles, and more reliable thread fits across components.