The JBO Thread Plug Gauge is a precision inspection tool designed for metric fine threads, purpose-built to verify the accuracy of threaded holes in machined parts and assemblies. It’s ideal for engineers, machinists, quality inspectors, and workshop technicians who need rapid, reliable checks to ensure parts fit together as intended.

With a Go/No-Go design, this gauge lets you quickly confirm whether a hole meets the required tolerance—streamlining QA workflows and reducing guesswork on the shop floor. Built from hardened steel, it delivers long-lasting wear resistance for repeated use in demanding environments, helping you maintain consistent results over time. The right-hand orientation and specification of M39 x 1 (6H) ensure compatibility with common metric fine-thread applications and standards.

• Go/No-Go design for fast, reliable checks: Quickly determine hole tolerance without trial assembly, saving time and preventing misfits.
• Hardened steel construction for lasting durability: Resists wear and maintains accuracy through frequent use in busy shops.
• Metric fine thread compatibility: M39 x 1, right-hand, 6H: Ensures precise, repeatable measurements aligned with standard metric practices.

This plug gauge helps you tighten quality control, improve workflow efficiency, and deliver consistent, dependable results in every threaded- hole inspection. It’s a straightforward, trustworthy tool that supports accurate assembly and reduces downtime across production, maintenance, and inspection tasks.