Spi 29-412-4 Class Zz Plus Plug Gage 0.412 in

Product Description

The SPI 29-412-4 is a Class ZZ Plus plug gage designed for precise go/no-go inspection of machined holes and bores. It measures a nominal diameter of 0.412 inches with a tolerance of 0.0002 inches, making it suitable for quality control work where tight dimensional verification is required. The gage is constructed from steel for durability and wear resistance. Machinists, toolroom technicians, and quality control inspectors use this type of plug gage to verify that drilled, reamed, or bored features fall within specified tolerances before parts advance to the next stage of production.

This plug gage is used in manufacturing, machine shop, and inspection environments where hole diameter conformance must be confirmed to close tolerances. Class ZZ designation indicates a commercial-grade tolerance class appropriate for general inspection of production parts. The 0.412-inch diameter targets holes produced by standard drilling or reaming operations in metalworking and fabrication shops.

Key Features

• Nominal measurement diameter of 0.412 inches for precise bore verification
• Tolerance of 0.0002 inches (0.0002 mm) for accurate Class ZZ Plus conformance
• Steel construction provides wear resistance and dimensional stability
• Class ZZ Plus rating suitable for commercial and production inspection applications
• Compact and lightweight at 0.2 pounds for easy handling during inspection

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for inspection of machined holes with a nominal diameter of 0.412 inches in standard metalworking and manufacturing quality control applications.

Installation Notes

Plug gages are handled and used by machinists and quality control technicians following shop inspection procedures. Clean the gage and the hole being checked before use to prevent debris from affecting the reading. Do not force the gage into an undersized hole, as this can damage the gage surface and compromise calibration. Store the gage in a protective case away from other tools to prevent nicking or corrosion of the precision surface.