Spi 19-318-5 Class Zz Minus Plug Pin Gage 0.318 in

Product Description

The SPI 19-318-5 is a Class ZZ minus plug pin gage designed for go/no-go dimensional inspection of bored holes, drilled passages, and machined features requiring close tolerance verification. The gage measures 0.318 inches in diameter and carries a tolerance of 0.0002 inches, placing it in the Class ZZ category suited for general-purpose inspection work. Manufactured from steel, this pin gage is a standard tool for quality control technicians, machinists, and inspection personnel verifying part conformance on the shop floor or in a metrology setting. The minus designation indicates the gage is ground to the lower boundary of the nominal diameter, consistent with standard plug gage convention.

This gage is used in manufacturing and fabrication environments where hole diameter verification is part of incoming inspection, in-process checks, or final part acceptance. It is appropriate for use on metal, plastic, and composite workpieces wherever a 0.318-inch nominal bore dimension must be confirmed. The compact form factor and single-pin design make it easy to integrate into manual inspection routines or fixture-based checking stations.

Key Features

• Class ZZ tolerance grade for general-purpose go/no-go hole inspection
• Minus designation ground to the lower boundary of the nominal diameter
• 0.0002 inch (0.0002 mm) tolerance for consistent measurement repeatability
• Steel construction for durability in shop and inspection room environments
• 0.318 inch nominal diameter covers common drilled and reamed bore sizes

Compatibility

Designed as a standard Class ZZ minus plug pin gage for general-purpose dimensional inspection of 0.318-inch nominal diameter bores in machined components and assemblies.

Installation Notes

Plug pin gages are handled and used by quality control technicians and machinists following standard metrology practices. Clean the gage and the bore being checked before use to prevent debris from affecting the reading or scoring the gage surface. Store the gage in its case or protective sleeve when not in use to prevent damage to the ground surface. Do not force the gage into an undersized bore, as this can alter the gage diameter and compromise accuracy.