Spi 23-217-3 Threaded Ring Gage 1-1/4-7 Class 2A Go No Go

Product Description

The SPI 23-217-3 is a double-ring threaded ring gage designed to verify external thread conformance on 1-1/4-7 UNC fasteners and threaded components to Class 2A tolerances. The set includes both a Go ring and a No Go ring in a single double-ring assembly, allowing technicians to confirm that a threaded part falls within the acceptable tolerance band without requiring two separate gages. Constructed from tool steel for dimensional stability and wear resistance, this gage meets NIST standards and ships with a traceability certification. It is used by machinists, quality control inspectors, and precision trade professionals who need reliable, documented thread verification on the shop floor or in the field.

This gage is suited for inspecting externally threaded fasteners, studs, bolts, and fittings produced to 1-1/4-7 UNC Class 2A specifications. It is a standard tool in manufacturing quality assurance, mechanical contracting, and industrial maintenance environments where thread fit and torque performance depend on confirmed dimensional compliance. The double-ring format streamlines inspection workflow by combining Go and No Go checks into one handling step.

Key Features

• Go and No Go rings combined in a single double-ring assembly for efficient thread inspection
• Class 2A classification covers the standard tolerance range for general-purpose external UNC threads
• Tool steel construction provides hardness and dimensional stability for repeated use
• Meets NIST standards with traceability certification included for documented quality processes
• Compact form factor: 3.25 inches wide, 0.77 inches in length, 4.168 pounds

Compatibility

Designed for inspection of externally threaded components with a 1-1/4-7 UNC thread form manufactured to Class 2A tolerance specifications.

Installation Notes

Threaded ring gages are used by machinists and quality inspectors and do not require installation in a mechanical system. Keep the gage clean and lightly oiled when not in use to prevent corrosion and preserve calibration. Do not apply the No Go ring with excessive force — a properly dimensioned thread should resist full engagement. Store the gage in its protective case and return it for recalibration per your facility's metrology schedule or applicable quality standards.