The JBO Thread Plug Gauge is a precision inspection tool designed for metric fine threads. It supports left-hand M5 x 0.5 holes and uses a clear Go/No-Go system to quickly confirm whether a threaded hole meets the required size. This makes it ideal for engineers, machinists, quality inspectors, and assembly teams working with tight tolerances. The Go/No-Go design helps you verify fit fast, reducing guesswork during setup and inspection.

Built for reliability, the gauge uses hardened steel to stand up to daily shop use and maintain accuracy over many cycles of insertion and removal.

• Left-Hand Metric Fine-Thread Go/No-Go Design: Quickly determine whether left-hand M5 x 0.5 holes meet spec, speeding up setup and quality checks.
• Precise M5 x 0.5, 6H Tolerance: Provides reliable go/no-go limits that align with standard metric threading, helping prevent misfits and rework.
• Hardened Steel Construction: Delivers long-lasting durability and consistent performance in busy workshop environments.

This plug gauge supports efficient quality control and dependable assembly outcomes. By delivering fast, repeatable checks, it helps you maintain consistent thread mating across parts, cut downtime, and improve overall throughput without sacrificing accuracy.