Spi 19-315-1 Class Zz Minus Plug Pin Gage 0.315 in

Product Description

The SPI 19-315-1 is a Class ZZ minus plug pin gage machined to a 0.315-inch nominal diameter with a tolerance of 0.0002 inches. Pin gages in the Class ZZ designation follow the looser tolerance grade established for production go/no-go inspection work, making this gage appropriate for checking hole sizes, slot widths, and clearance fits on the shop floor. The minus designation means the gage is ground below nominal, which is the standard configuration for go-gage applications. The steel construction provides the hardness and wear resistance needed for repetitive use in machining and fabrication environments. Machinists, quality technicians, and tool-and-die workers are the primary users.

This pin gage is used in dimensional inspection of drilled, reamed, or punched holes in production and job-shop settings. It is suited for both incoming inspection and in-process quality checks where a quick pass/fail determination on a hole diameter is required. The 0.315-inch size fits into gage handle sets that accept industry-standard pin gage blanks, making it easy to add to an existing set. It is commonly used in light manufacturing, aerospace component inspection, and general metalworking operations.

Key Features

• Class ZZ tolerance grade for production go/no-go inspection applications
• Minus designation ground below nominal for use as a go gage
• 0.0002-inch tolerance for reliable dimensional verification
• Steel construction for hardness and wear resistance in shop environments
• 0.315-inch nominal diameter for standard hole inspection tasks

Compatibility

Designed for use with standard pin gage handle sets that accept industry-standard pin gage blanks in the 0.315-inch diameter range. No specific system compatibility data was provided in the product input.

Installation Notes

Pin gages are handled and stored by quality technicians and machinists following standard metrology practices. Clean the gage and the workpiece bore before use to prevent false readings caused by debris or burrs. Store pin gages in a protective case or roll to prevent nicking the ground surface. Do not force a pin gage into an undersized hole, as this can damage the gage surface and compromise measurement accuracy.