The JBO Thread Plug Gauge is a precision Go/No-Go tool designed to inspect internal metric fine threads. It’s ideal for engineers, machinists, quality inspectors, and assembly teams that require fast, reliable thread verification with minimal guesswork.

Sized for left-hand M20 x 1 threads and 6G tolerance class, this gauge delivers durable performance in busy shops. The hardened steel construction resists wear, and the knurled body provides a secure grip for quick checks even in tight work areas.

• Go/No-Go quick inspection: Quickly determine if the internal threads meet spec with a simple pass/fail check, speeding setup and reducing guesswork.
• Left-Hand M20 x 1, 6G accuracy: Precisely sized for left-hand metric threads with 6G tolerance, ensuring consistent, repeatable checks across parts and batches.
• Hardened steel, durable construction: Built to resist wear in demanding environments, delivering long life and stable performance through daily use.

This gauge helps you validate threaded holes fast, reduces rework, and speeds up production without sacrificing accuracy. The durable construction means you can rely on it day after day, and the left-hand M20 x 1 sizing ensures you’re testing the exact threads used in final assemblies. In short, it brings precision, consistency, and confidence to every threading job.