The JBO Thread Plug Gauge is a UNEF Go-No/Go gauge designed for left-hand threads in the 15/16 x 20 size, built to Class 2B tolerances. It’s an essential inspection tool for machinists, quality teams, and maintenance technicians who work with threaded components in manufacturing, automotive, and aerospace environments. Its go/no-go design delivers fast, decisive checks to confirm whether a threaded hole meets the Unified thread standard, enabling proper fitment and reliable performance.

Two quick, accurate checks are all you need to confirm acceptance or rejection of a hole’s threading. This gauge’s precise UNEF left-hand dimensions ensure consistent, repeatable results, helping you speed up inspections without compromising accuracy.

• Go/No-Go simplicity for fast, unambiguous checks: Quickly determine if a hole conforms to UNEF left-hand 15/16 x 20 without guessing, reducing inspection time and rework.
• Precise UNEF left-hand 15/16 x 20 with 2B tolerance: Ensures consistent, repeatable measurements that align with standard thread specs, improving pass/fail accuracy across batches.
• Durable, shop-ready construction: Robust materials with a knurled grip and corrosion-resistant finish for reliable use in busy workshops and harsh environments.

Using this gauge helps streamline quality control, speed threaded-hole validation, and improve overall assembly performance. It supports confident decisions in production, minimizes downtime from misfits, and delivers reliable, repeatable results across manufacturing, automotive, and aerospace applications.