The JBO Thread Plug Gauge is a precision go/no-go tool designed to verify metric coarse threads inside tapped holes. This Left Hand model matches M4.5 x 0.75 coarse-thread specifications and provides fast, reliable checks to confirm proper fitment in assembled components.

Built for engineers, machinists, and assembly teams, the gauge helps you quickly decide whether a hole is within tolerance—accepting the go end and rejecting the no-go end—so you can move projects forward with confidence. Made from hardened steel, it delivers durable performance in busy workshops and long service life between calibrations.

• Go/No-Go design for fast checks: The quick pass/fail action lets you inspect threaded holes in seconds, reducing inspection time and rework while ensuring consistent results.
• Left Hand configuration for left-hand threads: Specifically suited for applications using left-handed thread assemblies, ensuring accurate verification without confusing right-hand gauges.
• Hardened steel with knurled grip: Built to withstand tough workshop use, the tool resists wear and offers secure, comfortable handling during repeated inspections.

This gauge helps you streamline quality control, prevent misfits, and keep production moving smoothly. By delivering reliable, repeatable measurements for M4.5 x 0.75 coarse threads, it supports better fitment, fewer downtime surprises, and longer tool life in your threading operations.