Spi 34-384-8 Plug Thread Gage 5/16-24 3B Double End

Product Description

The SPI 34-384-8 is a double-end plug thread gage designed to verify internal thread quality on 5/16-24 UNF threaded features. One end serves as the Go member to confirm minimum material condition, while the No Go end checks maximum material condition, together confirming conformance to Class 3B tolerance limits. The gage ships with a handle included and comes with NIST traceability certification, making it ready for immediate use in a calibrated quality-control environment. The steel construction provides durability through repeated inspection cycles on the shop floor or in a metrology lab.

This gage is used wherever precision internal thread verification is required on 5/16-24 UNF tapped holes. Typical applications include incoming inspection, in-process quality checks on machined components, and final acceptance testing in manufacturing, aerospace, automotive, and general mechanical assembly operations. The double-end design consolidates both Go and No Go functions into a single tool, reducing the number of gages a technician needs to manage at the inspection station.

Key Features

• Double-end design combines Go and No Go members in one tool
• Verifies 5/16-24 UNF internal threads to Class 3B tolerance
• NIST traceability certification included for calibration records
• Handle included — ready to use out of the package
• Steel construction for long service life under repeated use

Compatibility

Designed for inspection of 5/16-24 UNF internally threaded components requiring Class 3B thread tolerance verification.

Installation Notes

Thread plug gages are used by quality technicians and machinists — no power tools or utilities need to be shut off before use. Apply light hand pressure when threading the Go or No Go end into the part; never force the gage with a wrench or power driver, as this can damage both the gage and the part threads. Store the gage in its protective case when not in use and return it to calibration on the interval required by your quality management system to maintain NIST traceability.