Spi 29-431-4 Class Zz Plus Plug Gage 0.431 in Dia

Product Description

The SPI 29-431-4 is a Class ZZ Plus plug gage used to verify the diameter of machined holes to a precise 0.431-inch nominal size. It provides a go/no-go reference for quality control and inspection tasks on production floors and in machine shops. The gage holds a tolerance of 0.0002 inches, placing it in the Class ZZ Plus accuracy tier suited for general-purpose inspection of commercial-grade workpieces. The steel construction provides durability under repeated use. Machinists, quality technicians, and tool-and-die professionals rely on plug gages like this one to confirm bore dimensions before part acceptance or assembly.

This plug gage is appropriate for use in light manufacturing, job shop, and production inspection environments where hole diameter verification is required. It is a standard single-end gage format commonly used when checking drilled, reamed, or bored holes in metal and similar materials. At 0.431 inches, it fills a specific size requirement in a graduated gage set or serves as a standalone check for that exact nominal diameter.

Key Features

• 0.431-inch nominal measurement diameter for precise hole inspection
• Class ZZ Plus tolerance of 0.0002 inches for general commercial inspection work
• Steel construction for wear resistance and dimensional stability
• Compact and lightweight at 0.2 pounds for easy handheld use

Compatibility

Designed as a standard Class ZZ Plus plug gage for general-purpose hole inspection applications requiring a 0.431-inch nominal diameter check.

Installation Notes

Plug gages are used by quality control technicians and machinists and require no permanent installation. Handle the gage carefully to avoid dropping or contact with abrasive surfaces, as damage to the gage surface will affect measurement accuracy. Clean the gage and the workpiece bore before use to remove chips, oil, or debris. Store the gage in a protective case away from other tooling to prevent wear on the precision surface.