The JBO Thread Plug Gauge is a precision inspection tool designed for metric fine threads. Specifically tuned for M4 x 0.35 right-hand threads with 4H hole tolerance, it enables quick Go/No-Go checks to verify internal threads meet spec. Whether you’re in a production line, a machine shop, or performing field repairs, this gauge helps ensure threaded holes assemble correctly with minimal guesswork.

The gauge features a hardened steel construction for long-lasting performance in demanding environments. Its knurled body provides a secure grip for easy handling and precise orientation, even when wearing gloves.

• Go/No-Go design for fast, reliable checks: The go end confirms minimum engagement and the no-go end confirms the hole does not exceed tolerance, delivering quick pass/fail results in a single inspection.
• Hardened steel construction for durability: Built to resist wear and maintain measurement accuracy through heavy daily use in workshop conditions.
• Right-hand metric fine-thread compatibility (M4 x 0.35, 4H): Precisely matched to common internal threads, ensuring consistent results for parts designed for right-hand operation.

Using this gauge helps you streamline thread inspection, reduce rework, and improve overall assembly quality. The reliable Go/No-Go checks save time on every part, while the durable construction provides confidence that your measurements remain accurate shift after shift.