Spi 37-194-8 Plug Thread Gage M12x1.25 6H Go No Go

Product Description

The SPI 37-194-8 is a double-end plug thread gage designed to verify internal M12x1.25 threads to a 6H tolerance class. One end is the Go member; the other is the No Go member. When both ends are checked against a tapped hole, the technician confirms the thread is within the specified tolerance band. A handle is included. The gage meets ANSI standards with NIST traceability, making it appropriate for inspection environments that require documented calibration provenance. Machinists, quality control inspectors, and precision tool technicians use this gage on the shop floor or at a receiving inspection station.

This gage is used to inspect M12x1.25 fine-pitch internal threads in machined parts, castings, and fabricated components. The 6H classification indicates a standard commercial tolerance suitable for most threaded fastener applications. Double-end design consolidates both Go and No Go functions into a single tool, reducing handling time during high-volume inspection runs. It is well suited for production environments, job shops, and quality departments working to metric thread standards.

Key Features

• Go and No Go members on a single double-end handle for complete 6H thread verification
• M12x1.25 fine-pitch thread size for metric fastener and component inspection
• Handle included — ready to use out of the package
• ANSI-standard gage with NIST traceability certification included
• Compact profile: 4.62 inches in length, 0.58 inches in width and depth
• Lightweight at 0.22 pounds for extended inspection use

Compatibility

Designed for inspection of internal M12x1.25 threads manufactured to the 6H tolerance class per ANSI and NIST-referenced standards.

Installation Notes

Thread plug gages are inspection tools, not cutting tools — never force the Go end into an undersized hole or use the gage to chase threads. Handle the gage carefully to avoid nicks or burrs on the thread members, which would affect accuracy. Store the gage in its protective case when not in use and clean threads before each inspection. Periodic re-certification against a reference standard is recommended to maintain traceability.