Spi 29-471-0 Class Zz Plus Plug Gage 0.471 in

Product Description

The SPI 29-471-0 is a Class ZZ Plus plug gage designed for precise go/no-go inspection of machined bores and holes. Built from steel, this fixed-limit gage checks whether a hole falls within an acceptable tolerance range, making it a standard tool on the shop floor for machinists, toolmakers, and quality control technicians. It measures a nominal diameter of 0.471 inches with a tolerance of 0.0002 inches, giving inspectors a reliable reference for close-tolerance work. The Class ZZ designation indicates a commercial-grade tolerance class appropriate for production inspection where high-volume throughput is the priority.

This plug gage is suited for use in manufacturing environments where bore dimensions must be verified to print specifications. Typical applications include inspection of drilled, reamed, or bored holes in metal components across general machining, automotive, aerospace, and tooling operations. The 0.471-inch diameter makes it a purpose-specific tool for a defined nominal hole size, and it is used as part of a go/no-go gage set or as a standalone check gage at a single nominal dimension.

Key Features

• Class ZZ Plus tolerance class for production-grade bore inspection
• 0.471-inch nominal measurement diameter for a defined nominal hole size
• 0.0002-inch tolerance for close-tolerance go/no-go verification
• Steel construction for durability and wear resistance in shop environments
• Compact and lightweight at 0.2 pounds for easy single-hand use

Compatibility

Designed as an OEM-style inspection tool for verifying 0.471-inch nominal bore diameters in general production and quality control applications.

Installation Notes

Plug gages are handled and used by machinists and quality control technicians — no installation in the traditional sense is required, but proper handling practice applies. Clean the gage and the workpiece bore before gauging to remove chips, oil, and debris that could cause a false reading. Never force a plug gage into a hole; hand pressure only is the correct technique. Store the gage in a protective case away from other tooling to prevent nicks and wear that would compromise accuracy.