The JBO Thread Ring Gauge GO - UNF - Left Hand - 2A - No. 1 x 72 is a precision inspection tool designed to verify external thread diameters with confidence. It’s ideal for engineers, machinists, quality teams, and workshop technicians who need to confirm that UNF left-hand threads meet the required diameter.

Made from hardened steel, this GO ring gauge delivers durable, long-lasting performance in demanding work environments and supports repeatable measurements during routine inspections.

• Hardened steel construction: Built for daily use, this gauge resists wear and maintains accuracy across many inspections in busy shops.
• Precise UNF left-hand GO gauge (2A class): Accurately checks external threads to ensure components conform to UNF standards, helping prevent misfits and rework.
• User-friendly inspection design: Designed for quick identification of conforming threaded parts, speeding up quality checks and reducing inspection time.

By delivering reliable, go/no-go verification in a compact tool, the JBO Thread Ring Gauge streamlines your quality control workflow, reduces downtime from incorrect threading, and supports consistent, repeatable results across batches. Its robust hardened steel construction and proven design help you maintain thread accuracy over the life of your shop.