The JBO Thread Ring Gauge (NoGo) — Metric Fine, Left Hand, 6g, M39 x 1.5 — is a precision inspection tool designed to verify external thread diameters. It’s ideal for manufacturers, machinists, and quality-control teams who need fast, reliable checks to ensure parts meet exact thread specifications.

Crafted from hardened steel for exceptional wear resistance, this NoGo gauge stands up to daily use in demanding workshops. Its precise dimensions make it easy to identify threads that are out of spec, helping you maintain consistent quality and reduce rework.

• Durable hardened steel construction: Built to withstand repeated use in busy shops, providing long-lasting accuracy and reduced replacement costs.
• Precise metric fine NoGo verification: Designed for M39 x 1.5 left-hand threads with 6g tolerance, enabling quick, reliable pass/fail checks against specifications.
• Easy-to-use, non-destructive checks: The smooth inner bore and clear edge deliver rapid, non-marring verification, helping you identify non-conforming threads fast.

With the JBO NoGo Thread Ring Gauge, you gain faster, more reliable thread verification, reducing inspection time and rework. The hardened steel construction delivers lasting performance in demanding environments, while the clear NoGo threshold and metric fine specification keep your quality control consistent across batches. Whether in manufacturing, assembly, or repair work, this gauge helps your team confirm fit and tolerance with confidence.