Spi 23-153-0 Threaded Ring Gage 1/4-28 Class 2A Go No Go

Product Description

The SPI 23-153-0 is a double-ring threaded ring gage set used to inspect external threads for dimensional conformance. It includes both a Go ring and a No Go ring in a single package, allowing technicians to verify that a threaded fastener or shaft falls within the accepted tolerance range for a 1/4-28 UNF thread form. Manufactured from tool steel for durability and wear resistance, this gage is built to NIST-traceable standards and ships with a traceability certification. It is used in machining, fabrication, and quality control environments where thread verification is part of the inspection process.

This gage is suited for inspecting 1/4-28 UNF external threads classified to Class 2A tolerance, which represents the standard fit used in the majority of general-purpose fastener applications. It is commonly used on production floors, in tool cribs, and at inspection stations where machinists, quality control technicians, and maintenance professionals need a fast, reliable method to accept or reject threaded parts without relying on measuring instruments alone.

Key Features

• Double-ring design provides both Go and No Go gages in one unit
• 1/4-28 UNF thread size with Class 2A classification
• Tool steel construction for long service life under repeated use
• NIST-traceable calibration with traceability certification included
• Compact form factor fits standard gage storage and tool crib organization

Compatibility

Designed for inspection of 1/4-28 UNF external threads conforming to Class 2A tolerance standards. Verify thread form and pitch match before use on any threaded workpiece.

Installation Notes

Threaded ring gages are used by quality control technicians and machinists and do not require power or fluid shutoff prior to use. Keep the gage clean and lightly oiled when not in use to prevent corrosion and dimensional drift. Do not force the gage onto a thread; if the Go ring does not pass freely, the thread is out of tolerance. Store in a protected case away from impact or temperature extremes to maintain calibration integrity.