Spi 29-525-3 Class Zz Plus Plug Gage 0.525 in

Product Description

The SPI 29-525-3 is a Class ZZ Plus plug gage designed for checking hole diameters to a nominal size of 0.525 inches with a tolerance of 0.0002 inches. Plug gages in this class are used for go/no-go dimensional inspection of bored, drilled, and reamed holes in machined components. The steel construction provides durability for repeated use in shop-floor and quality-control environments. Machinists, tool-and-die makers, and quality technicians use this type of gage to verify conformance to tight dimensional tolerances without relying on calipers or micrometers alone.

This gage is suited for production inspection and incoming quality control in manufacturing and fabrication settings. It is used wherever a 0.525-inch nominal hole diameter must be verified against a specified tolerance. Typical applications include inspection of machined housings, fixtures, and precision mechanical assemblies. The Class ZZ Plus designation indicates a higher accuracy tolerance class appropriate for general-purpose production gaging where reliable go/no-go verification is required.

Key Features

• Nominal diameter of 0.525 inches for direct hole-size verification
• Class ZZ Plus tolerance of 0.0002 inches for accurate go/no-go inspection
• Steel construction for wear resistance and dimensional stability
• Compact and lightweight at 0.2 pounds for easy handling during inspection
• Single-piece packaging for individual replacement or kit supplementation

Compatibility

Designed as a standard go/no-go plug gage for use with any handle or gage holder that accepts a 0.525-inch diameter gage member, consistent with general-purpose Class ZZ plug gage applications in production inspection.

Installation Notes

Plug gages are handled and used by machinists and quality control technicians — no installation in the traditional sense is required. Before use, ensure the gage and the workpiece bore are clean and free of chips, coolant, and debris to prevent false readings or damage to the gage surface. Do not force the gage member into an undersized hole, as this can damage the gage or the workpiece. Store the gage in a protective case away from other metal tools to prevent surface damage that would affect calibration accuracy.