The JBO Thread Ring Gauge (NoGo) for UNC left-hand threads is a precision inspection tool designed to verify external thread diameters on LH components. Sized for a 1 3/8" major diameter with 6 threads per inch and built to Class 2A tolerance, it helps ensure parts meet Unified thread standards across manufacturing, automotive, and aerospace applications.

Crafted from hardened steel, this gauge delivers durability in busy workshops and QC environments. The NoGo design makes non-conforming threads easy to spot at a glance, speeding up inspections and reducing the risk of incorrect assemblies.

• NoGo design for fast conformance checks: Quickly identifies oversized or undersized threads to enable fast pass/fail decisions, reducing rework and downtime.
• Left-hand UNC 1 3/8 x 6 compatibility: Precisely matched to UNC LH threads (1 3/8 x 6, 2A), ensuring accurate verification and preventing incorrect mating in LH assemblies.
• Hardened steel construction for long life: Durable, wear-resistant material that maintains dimensional stability through repeated use in demanding environments.

By delivering fast, reliable thread verification, this gauge helps protect assembly quality, reduce downtime, and streamline quality control workflows. It provides confidence that LH UNC threads conform to standard specifications, supporting consistent fitment and safer, more reliable performance across finished parts and assemblies.