The JBO Thread Plug Gauge (GO) – Metric Coarse, Left Hand, 6H, M42 x 4.5 is a precision Go gauge designed to quickly verify threaded holes meet metric coarse standards. Tailored for left-hand thread applications, it ensures holes will accept the intended components and conform to tight dimensional requirements across manufacturing, assembly, and maintenance workflows.

Ideal for quality control teams, machinists, engineers, and inspectors, this GO gauge delivers fast, repeatable pass/fail checks that reduce guesswork and rework. Crafted from hardened steel, it resists wear in demanding environments and maintains accuracy through frequent use.

• Go Gauge for Metric Coarse Threads: Provides fast, one-pass validation of hole size to metric coarse standards, enabling quick decisions and consistent assemblies.
• Durable Hardened Steel Construction: Built for daily shop use, delivering long tool life and reliable performance even in busy production environments.
• Left-Hand Thread Form Compatibility (M42 x 4.5, 6H): Precisely matched to left-hand coarse thread specifications, ensuring correct testing for the intended components and workflow.

Using the JBO GO gauge helps streamline inspection, accelerate quality checks, and improve first-pass acceptance. Its precise, repeatable measurements support reliable thread mating, reduce downtime from misfits, and provide confidence for audits and handovers across engineering and manufacturing teams.