The JBO Thread Ring Gauge (GO) for UNC left-hand threads is a precision inspection tool designed to verify external thread diameters on fasteners, fittings, and machined components. It helps quality teams and technicians quickly confirm that parts meet UNC left-hand thread specifications with reliable Go measurements.

Built for durability and long life, this ring gauge uses hardened steel and a rugged finish to resist wear in busy shops, manufacturing floors, and field service environments. With a 1 1/4 x 7 size and 2A tolerance, it’s tailored for applications requiring accurate Go/no-go checks of left-handed UNC threads.

• Go/No-Go verification for UNC left-hand threads: Provides quick, reliable checks on external diameters to confirm conformity with 1 1/4 x 7 UNC left-hand specifications, reducing guesswork in inspection.
• Hardened steel construction: Delivers exceptional wear resistance and durability for daily use in machining shops, QC labs, and field service environments.
• Consistent, repeatable measurements: Tight tolerances with 2A class engagement ensure dependable results across multiple parts and inspection cycles.

With the JBO Thread Ring Gauge (GO), inspectors gain confidence that every component meets thread standards, speeding up acceptance checks, reducing rework, and supporting compliant assembly across production lines. Its durable build and precise dimensions translate to fewer measurement errors, smoother QC workflows, and long-term reliability in demanding work environments.