JBO Thread Plug Gauge (NoGo) - Metric Fine - Left Hand - 6H - M55 x 1 is a precision tool designed to verify threaded holes with metric fine threads. This NoGo plug gauge helps you quickly determine whether a hole is at the maximum material condition for left-hand, M55 x 1 threads, aligned with the 6H tolerance class. It’s ideal for quality control, machining shops, and assembly environments where accurate hole sizing matters.

Crafted for durability and reliable performance, the gauge is made from hardened steel to resist wear in demanding work settings, ensuring consistent results over time.

• NoGo verification for metric fine threads: Quickly confirm maximum material condition on holes with metric fine threads, reducing inspection time and preventing out-of-spec components from passing.
• Hardened steel construction for durability: Built to resist wear and maintain dimensional integrity through frequent use in busy workshops.
• Left-Hand, metric fine sizing (M55 x 1, 6H) with knurled grip: Specifically calibrated for left-hand thread holes, and finished to the 6H class size, the knurled handle provides secure, comfortable use for quick, repeatable checks.

Using the JBO Thread Plug Gauge (NoGo) elevates your measurement discipline by delivering fast, reliable checks on metric fine, left-hand holes. It helps you lock in consistent hole sizes, speeds up QA workflows, and reduces downtime due to misfits, so your team can assemble with confidence and maintain high-quality output across production runs.