The JBO Thread Ring Gauge (NoGo) - UNC - Right Hand - 2A - No. 4 x 40 is a precision tool designed to verify external UNC threads. Whether you’re in manufacturing, automotive, or aerospace, this NoGo gauge helps you quickly confirm that threaded components meet standard UNC threads and tolerance class 2A.

It features a NoGo design for fast, at-a-glance identification of non-conforming threads, reducing guesswork during inspection and assembly. Crafted from hardened steel, it’s built to withstand routine use on busy shop floors while delivering repeatable, reliable checks.

• NoGo design for fast pass/fail verification: Quickly identify non-conforming threads and prevent incorrect assemblies, boosting throughput and reducing rework.
• UNC Right Hand, 2A, No. 4 x 40 sizing: Provides precise, standards-aligned measurements for the most common external thread configuration, ensuring reliable inspection results across batches.
• Hardened steel construction: Delivers long-lasting durability under routine use, resisting wear and maintaining measurement accuracy over time.

Used as a trusted reference in quality control, this gauge speeds up inspections, promotes consistency in threaded components, and supports compliance with UNC standards. By delivering clear pass/fail signals and enduring reliability, it helps your team reduce downtime, minimize rework, and achieve dependable, compliant results across production runs.