Spi 34-271-7 Plug Thread Gage 3/8-24 6H Single End Go

Product Description

The SPI 34-271-7 is a single-end Go plug thread gage machined from steel and used to verify the dimensional accuracy of internal threaded features. It checks that a 3/8-24 UNF threaded hole meets the minimum material condition for proper fit. Classified to the 6H tolerance standard under ANSI, this gage provides a pass/fail check when thread accuracy is critical to assembly integrity. It is used by machinists, quality control inspectors, and tool-room technicians in manufacturing, fabrication, and precision assembly environments. A Size 2 handle is required for use but is not included with this gage.

This plug thread gage is suited for inspection of 3/8-24 UNF internal threads in production and quality assurance settings. Typical applications include verifying threaded bores in machined components, fastener assemblies, and precision mechanical parts where thread class conformance must be documented. The Go member confirms that a threaded hole will accept a mating fastener within tolerance. NIST traceability certification is included, making this gage appropriate for use in calibration-documented inspection programs and ISO-compliant quality systems.

Key Features

• Go member only — confirms minimum material condition on 3/8-24 UNF internal threads
• 6H classification per ANSI standards for close-tolerance thread inspection
• Steel construction for durability in production inspection use
• NIST traceability certification included for calibration-documented workflows
• Single-end design; accepts a Size 2 handle (handle sold separately)
• Complies with ANSI and NIST standards

Compatibility

Designed for inspection of 3/8-24 UNF internal threaded features classified to the 6H tolerance standard. Requires a Size 2 plug gage handle, which is not included.

Installation Notes

Plug thread gages are installed and operated by machinists or quality inspectors; no power source is required. Secure the gage in a compatible Size 2 handle before use. Keep the gage clean and lightly oiled when stored to prevent corrosion and protect calibrated surfaces. Do not force the Go member through a threaded hole — hand-tight engagement under light torque is the correct method.