Spi 19-478-7 Class Zz Minus Plug Pin Gage 0.478 in Dia

Product Description

The SPI 19-478-7 is a Class ZZ minus plug pin gage with a 0.478-inch nominal diameter, manufactured from steel for use in precision dimensional inspection. Plug pin gages are go/no-go style tools used to verify bore diameters, hole sizes, and internal feature tolerances to tight specifications. The Class ZZ designation indicates a tolerance grade suited for production inspection and shop-floor quality control applications. This gage carries a tolerance of 0.0002 inches and is built to minus tolerancing convention, meaning the gage is ground below nominal to reduce wear risk on the part being checked. Machinists, quality technicians, and tool-and-die professionals use these gages as part of routine dimensional verification workflows.

This plug pin gage is appropriate for production and inspection environments where bore size conformance must be verified against a defined tolerance. It is commonly used in machine shops, manufacturing facilities, and quality control labs. The 0.478-inch diameter addresses a specific bore size in general metalworking and mechanical assembly applications. The steel construction supports repeated use in shop environments where contact with machined surfaces is routine.

Key Features

• Class ZZ tolerance grade suitable for production-level inspection
• Minus tolerance ground below nominal at 0.0002 inches
• 0.478-inch nominal diameter for precision bore verification
• Steel construction for durability under repeated shop-floor use
• Single-piece packaging suitable for individual replacement or inventory replenishment

Compatibility

Designed as a standard Class ZZ minus plug pin gage for use in any application requiring verification of a 0.478-inch nominal bore diameter within production or quality control inspection setups.

Installation Notes

Plug pin gages are handled and used by quality technicians and machinists during inspection — no power-down or mechanical installation is required. Handle the gage with clean cotton gloves or a lint-free cloth to prevent corrosion from skin contact. Store in a protective case away from temperature extremes and contamination to preserve calibration integrity. Do not force the gage into a bore; if resistance is felt, the bore is undersize and the gage should be withdrawn without applying additional pressure.