Spi 19-319-3 Class Zz Minus Plug Pin Gage 0.319 in

Product Description

The SPI 19-319-3 is a Class ZZ minus plug pin gage designed to verify bore and hole diameters with high precision. Built from steel, this pin gage measures 0.319 inches in diameter and carries a tolerance of 0.0002 inches, placing it in the Class ZZ specification for general inspection and shop-floor gauging work. The minus designation means the gage is manufactured to the low side of the nominal diameter, a standard approach for go/no-go inspection of female features. Machinists, quality control technicians, and tool-room professionals use pin gages like this to confirm that drilled, reamed, or bored holes meet print tolerances before parts move to the next operation.

This pin gage is suited for use in production inspection, incoming quality checks, and setup verification across machine shops, job shops, and manufacturing facilities. It is appropriate for checking hole size conformance in metal, plastic, and composite workpieces where a 0.319-inch nominal diameter is specified. Class ZZ gages are commonly used in general commercial inspection rather than laboratory-grade metrology, making them a practical choice for day-to-day shop use.

Key Features

• 0.319-inch nominal diameter for direct measurement of corresponding bore sizes
• Class ZZ classification meets standard commercial inspection requirements
• Minus tolerance designation ensures the gage falls on the low side of nominal
• 0.0002-inch tolerance for reliable shop-floor precision
• Steel construction for durability under repeated use

Compatibility

Designed as a standard Class ZZ minus plug pin gage suitable for general inspection of 0.319-inch diameter holes and bores in typical machining and manufacturing applications.

Installation Notes

Pin gages should be handled with clean, dry hands or lint-free gloves to prevent corrosion from skin oils. Before use, verify the gage and the workpiece bore are at the same ambient temperature to avoid measurement error from thermal expansion. Store the gage in its protective case when not in use and inspect it periodically for wear or damage that could affect accuracy. Calibration should be traceable to national standards and performed at intervals appropriate to the frequency of use.