Spi 34-286-5 Plug Thread Gage 1/2-13 6H Single End Go

Product Description

The SPI 34-286-5 is a single-end Go plug thread gage designed to verify internal thread conformance on 1/2-13 UNC threaded features. Machined from steel, this gage checks that a threaded hole or nut meets the minimum material condition for 6H class tolerance, confirming threads will accept a mating fastener without interference. It is a standard inspection tool used in manufacturing, maintenance, and quality control environments where thread integrity must be confirmed before assembly. Traceability certification to NIST standards is included, supporting calibration documentation requirements. A size 2 handle is required for use but is not included with this gage.

This gage is suited for inspection of 1/2-13 UNC threaded holes in metal fabrication, HVAC equipment assembly, industrial maintenance, and general mechanical work. The Go member confirms that threads are cut to the correct pitch diameter minimum, allowing a mating bolt or stud to engage properly. Machinists, quality technicians, and maintenance professionals use single-end Go gages as part of a two-gage Go/No-Go inspection routine. The separate No-Go gage must be sourced independently to complete a full tolerance check.

Key Features

• Go-type plug gage checks minimum pitch diameter conformance on 1/2-13 UNC internal threads
• 6H class tolerance rating consistent with ANSI standards for general-purpose inch threads
• Steel construction for durability and dimensional stability under repeated use
• NIST traceability certification included for calibration records and quality documentation
• Single-end design — requires a size 2 handle, sold separately
• Conforms to ANSI and NIST standards

Compatibility

Designed for inspection of 1/2-13 UNC internal threads manufactured to 6H class tolerance per ANSI standards. Accepts a standard size 2 plug gage handle, not included.

Installation Notes

Thread gages should be installed onto a size 2 handle before use; do not force the gage member into a threaded feature. Clean threads of chips, oil, and debris before gaging to ensure accurate readings. Gages are precision instruments and should be stored in a protective case when not in use to prevent damage to the thread form. Periodic recalibration against NIST-traceable masters is recommended to maintain measurement integrity.