Spi 34-320-2 Plug Thread Gage 3/4-20 6H No Go Single End

Product Description

The SPI 34-320-2 is a single-end No Go plug thread gage designed to verify that internally threaded workpieces do not exceed maximum material condition tolerances. Built to a 6H classification, this gage checks 3/4-20 UNF threads and is used in quality control and inspection workflows to reject out-of-tolerance parts before assembly. The gage body is machined from steel for dimensional stability and wear resistance. It ships without a handle; a Size 3 handle is required for use and must be sourced separately. NIST traceability certification is included, satisfying most shop-floor and calibration lab documentation requirements.

This No Go plug thread gage is appropriate for machine shops, manufacturing facilities, aerospace component suppliers, and any production environment where threaded fastener or fitting acceptance criteria must be verified to ANSI standards. It is suited for inspection of 3/4-20 UNF tapped holes in metal components where fit and function depend on thread tolerance compliance. Single-end configuration keeps the gage compact and straightforward to use at a workbench or inline inspection station.

Key Features

• No Go member only — single-end design for dedicated rejection checking of out-of-tolerance 3/4-20 UNF threads
• 6H tolerance class per ANSI standards for precise internal thread verification
• Steel construction provides durability and dimensional stability under repeated use
• NIST traceability certification included for calibration and quality system compliance
• Requires Size 3 handle (not included) — compatible with standard plug gage handle systems
• Meets ANSI and NIST standards for thread gage accuracy and traceability

Compatibility

Designed for use with a standard Size 3 plug gage handle (sold separately) and intended for inspection of 3/4-20 UNF internally threaded workpieces requiring 6H class tolerance verification.

Installation Notes

Thread gages should be installed and used by qualified inspection or machining personnel familiar with ANSI thread gage standards and proper gage handling procedures. Secure the gage in a Size 3 handle before use; never apply the gage member directly without a properly fitted handle. Keep the gage clean and lightly oiled when not in use to prevent corrosion and preserve calibration accuracy. Do not force the No Go member into a threaded hole; a properly toleranced thread should resist full engagement.