The JBO Thread Plug Gauge is a precision Go/No-Go tool crafted for metric fine threads. It’s the reliable choice for engineers, machinists, technicians, and hobbyists who need fast, accurate checks to confirm threaded holes will accept the corresponding fasteners. With its right-hand thread orientation and a fine pitch of M39 x 1.5, it helps ensure perfect fits in assemblies where precision matters.

Built from hardened steel for lasting performance, this gauge is designed to withstand daily use in busy workshops. The knurled body provides a confident grip even with oily hands, and the Go/No-Go design lets you verify hole tolerance in seconds—reducing guesswork and rework.

• Go/No-Go design for fast, confident hole checks: Quickly verify whether a threaded hole meets the required tolerance, enabling immediate pass/fail decisions and smoother workflows.
• Metric fine-thread compatibility (M39 x 1.5, 6H): Precisely matches the intended thread form, helping ensure reliable engagement and correct component mating in fine-pitch applications.
• Hardened steel construction for long life: Built to resist wear and maintain accuracy over many inspections, even in demanding environments.

This plug gauge streamlines inspection and assembly, speeding up production and maintenance tasks while increasing confidence in every fit. By delivering clear Go/No-Go results, it helps you capture consistent quality, reduce scrap, and keep projects on schedule with fewer surprises.