Spi 19-531-3 Class Zz Minus Plug Pin Gage 0.531 in

Product Description

The SPI 19-531-3 is a Class ZZ minus plug pin gage machined to a 0.531-inch nominal diameter with a minus tolerance of 0.0002 inches. Plug pin gages are precision go/no-go inspection tools used to verify bore and hole diameters to a known standard. The minus designation means the gage diameter is ground below the nominal, making it suitable for checking minimum material condition in close-tolerance applications. Constructed from steel, this gage is a standard instrument in quality control and machining environments where dimensional verification is required before assembly or final inspection sign-off.

This gage is used in machine shops, manufacturing cells, and inspection departments where hole diameter conformance must be confirmed to tight tolerances. It is appropriate for verifying drilled, reamed, or bored holes in production and toolroom settings. The 0.531-inch diameter targets a commonly specified hole size across a range of mechanical assemblies. Machinists, quality technicians, and tool-and-die professionals use Class ZZ gages for general-purpose inspection work where gage-block-grade accuracy is not required but reliable dimensional verification is still essential.

Key Features

• Class ZZ tolerance grade suited for general-purpose go/no-go hole inspection
• Minus plug designation ground below nominal for minimum material condition checks
• 0.0002-inch tolerance for reliable dimensional verification
• Steel construction for durability and dimensional stability in shop environments
• 0.531-inch nominal diameter covers a standard hole size used across mechanical assemblies

Compatibility

Designed as a standard Class ZZ minus plug pin gage for general-purpose inspection of 0.531-inch nominal diameter bores and holes in production and toolroom applications.

Installation Notes

Plug pin gages are handled and used by quality technicians and machinists following standard metrology practices. Clean the gage and the hole being measured before use to prevent debris from affecting readings. Store the gage in its protective sleeve or case when not in use to avoid surface damage and corrosion. Do not force the gage into a hole; forced insertion can damage both the gage and the workpiece and will produce unreliable inspection results.