The JBO Thread Plug Gauge is a UNF go/no-go plug gauge designed for quick, reliable verification of internal threads. It’s ideal for manufacturing, automotive, and aerospace settings where fast, accurate thread inspection is essential. The go/no-go design lets operators confidently confirm whether a threaded hole meets the required standard at a glance, helping to keep production moving and quality consistent.

This left-hand version is sized for UNF threads at 1 3/8 x 12 with a 2B tolerance, ensuring precise, repeatable measurements across tools and operators. Crafted from hardened steel with a durable finish, it stands up to daily use in busy shop environments and maintains accurate readings over time.

• Go/No-Go quick verification: Instantly confirm conforming versus non-conforming threads, speeding inspections and reducing guesswork on the shop floor.
• Exact UNF left-hand size (1 3/8 x 12) with 2B tolerance: Precise, standards-compliant dimensions that deliver consistent results for reliable hole validation in left-hand applications.
• Rugged, ergonomic construction: Hardened steel, precise threading ends, and a knurled body provide durable, comfortable handling for repeated use and easy alignment in tight spaces.

Designed to improve inspection efficiency and accuracy, the JBO Thread Plug Gauge helps you validate threaded holes with confidence. Its precise size and robust build support repeatable measurements across shifts and machines, reducing downtime and nonconforming parts. A dependable, long-lasting addition to any quality lab, maintenance bay, or production line.