The JBO Thread Plug Gauge is a precision tool designed for testing internal UNC left-hand threads in holes and threaded fittings. Built for manufacturers, automotive shops, aerospace facilities, and serious hobbyists, it provides fast, on-the-spot verification of thread conformity using a clear Go/No-Go result. Sized for 1 3/8 in. x 6 in. UNC left-hand threads with 2B tolerance, this gauge helps ensure proper fit and reliable assembly.

• Go/No-Go design: Quickly determine if the internal threads are within tolerance, delivering a simple pass/fail result that speeds quality checks and reduces measurement guesswork.
• Ergonomic, durable construction: Knurled grip and robust metal ends provide secure handling and long-lasting performance in demanding workshop environments.
• Precisely matched size and tolerance: Engineered for 1 3/8 x 6 UNC left-hand threads with 2B tolerance, ensuring consistent checks across use and operators.

Using the JBO Thread Plug Gauge streamlines your threaded-hole inspection routine. It offers a fast, visual test for Go and No-Go conditions, helping prevent misfit assemblies, minimize downtime, and keep production moving. The durable construction and exact sizing deliver repeatable results across shifts, so you can rely on consistent quality with every check.