The JBO Thread Plug Gauge is a precision Go/No-Go tool designed to verify internal metric fine threads. Specifically built for M20 x 0.75 left-hand threads, it helps ensure threaded holes meet exact size and tolerance during assembly and quality checks.

Constructed from hardened steel, this gauge delivers durable, repeatable results in busy machine shops, production lines, and inspection labs. Its compact plug form makes it easy to carry between workstations and use as part of standard go/no-go procedures.

• Go/No-Go quick verification: Two fast checks tell you whether the hole is within tolerance, enabling quick pass/fail decisions on the shop floor.
• Durable hardened steel construction: Hardened steel withstands repeated use and resists wear, helping maintain accuracy and extending tool life.
• Left-hand M20 x 0.75, 6H precision fit: Precisely sized to the specified thread and tolerance class, delivering consistent measurements for reliable hole verification.

Using this gauge speeds up quality control, reduces rework, and provides confidence that components will assemble correctly. It supports efficient inspections at various stages—from incoming parts to final assembly—delivering consistent, dependable results across production runs.