Spi 23-173-8 Threaded Ring Gage 7/16-28 Class 2A Go No Go

Product Description

The SPI 23-173-8 is a double-ring threaded ring gage used to inspect external threads to the 7/16-28 thread specification at Class 2A tolerance. It includes both a Go ring and a No Go ring in a single double-ring configuration, allowing technicians to confirm both the maximum material condition and the minimum thread acceptance boundary without switching tools. Made from tool steel and supplied with NIST traceability certification, this gage is suited for production floor inspection, incoming quality control, and precision machining verification. Machinists, QC inspectors, and toolroom technicians are the primary users of this type of gage.

This gage is applied wherever 7/16-28 externally threaded components must be verified for dimensional conformance prior to assembly or shipment. The 7/16-28 designation refers to a 7/16-inch nominal diameter with 28 threads per inch, a fine-pitch thread used in precision mechanical and instrument applications. The Class 2A classification corresponds to standard tolerance limits for general-purpose external threads as defined under ASME B1.2. Both Go and No Go members are contained in the double-ring body, making it efficient for high-volume thread inspection workflows.

Key Features

• Double-ring design includes both Go and No Go members in one unit for streamlined inspection
• Covers 7/16-28 thread size at Class 2A external thread tolerance
• Constructed from tool steel for durability and wear resistance in production environments
• NIST traceability certification included, supporting quality system documentation requirements
• Compact form factor suitable for bench use or in-line inspection

Compatibility

Designed for inspection of external threads conforming to the 7/16-28 thread form at Class 2A tolerance limits per ASME B1.2 standards.

Installation Notes

Threaded ring gages are used by machinists and quality control inspectors and require no installation in the traditional sense. Before use, ensure the gage and the part being inspected are at the same ambient temperature to avoid thermal expansion error. Apply light thread-cutting oil or gage oil when gaging to reduce wear on the gage rings. Store the gage in its case when not in use and have it recalibrated periodically per your quality system requirements to maintain NIST traceability.