The JBO Thread Plug Gauge is a UNC Go-No/Go plug gauge built for fast, reliable verification of threaded holes to the Unified thread standard. With right-hand threads, a 2B class tolerance, and a 5/16 x 18 size, it helps quality teams confirm correct hole fitment in parts across manufacturing, automotive, and aerospace environments.

Designed for inspectors, machinists, and buyers alike, this compact gauge makes go/no-go checks straightforward, so you can confirm conformance at a glance without trial fittings or guesswork.

• Fast go/no-go verification: Quickly differentiate between conforming and non-conforming threads, reducing inspection time and the risk of improper assemblies.
• Standard-compatible sizing: Precisely matches UNC 5/16 x 18 with a 2B tolerance so you’re testing the actual hole size and avoiding ambiguity in acceptance decisions.
• Rugged, easy-handling design: Knurled metal body and robust ends provide a secure grip and long service life in busy workshops, even with gloves or oil on hands.

The JBO Thread Plug Gauge helps you accelerate quality control, improve repeatability, and safeguard assemblies by delivering dependable thread checks that align with standard specifications. Its durable construction and precise dimensions give you confidence to rely on it daily for consistent results across parts and suppliers.