The JBO Thread Plug Gauge is a precision Go/No-Go tool designed specifically for metric fine threads. This Left Hand version is ideal for inspectors, machinists, and assembly technicians who need fast, reliable checks of internal holes to confirm a proper M4 x 0.35 thread fit.

Built with hardened steel for long-lasting performance, the gauge resists wear through repeated use in busy shops. The Go/No-Go design makes quick pass/fail decisions that help keep production moving and ensure consistent results within the 6H tolerance class.

• Go/No-Go quick checks: Quickly verify hole readiness with simple go/no-go checks, speeding up inspections and reducing guesswork during assembly.
• Metric fine thread compatibility: Precisely checks M4 x 0.35 internal threads to ensure proper mating with components that require fine-pitch screws.
• Hardened steel construction: Designed to withstand daily workshop use, resisting wear and maintaining accuracy for long-term reliability.

Using this gauge, you gain confidence in every assembly: faster QC, fewer returns, and consistent results across lots. Its durability and precise tolerances reduce rework and downtime, helping you meet tighter schedules and quality standards more reliably.