Spi 19-381-3 Class Zz Minus Plug Pin Gage 0.381 in

Product Description

The SPI 19-381-3 is a Class ZZ minus plug pin gage with a 0.381-inch nominal diameter, manufactured from steel for reliable dimensional inspection in precision measurement applications. This gage is used to verify hole diameters and bore tolerances, providing a go/no-go reference for quality control work. It carries a tolerance of 0.0002 inches in the minus direction, conforming to Class ZZ specifications. Machinists, toolmakers, and quality control technicians use plug pin gages like this one to check that drilled, reamed, or bored holes fall within acceptable dimensional limits during production and inspection workflows.

This pin gage is suited for shop-floor and inspection-room use in manufacturing, metalworking, and precision machining environments. Class ZZ gages are generally applied to production-level inspection where commercial-grade tolerance verification is required. The 0.381-inch diameter targets holes in that specific size range and is part of a larger incremental gage family for systematic hole checking across a range of diameters.

Key Features

• Class ZZ minus tolerance designation for production-level hole inspection
• Nominal diameter of 0.381 inches for targeted bore verification
• Tolerance of 0.0002 inches (0.0002 mm) for precise dimensional control
• Steel construction for durability in shop-floor environments
• Single-piece package quantity suitable for individual replacement or kit building

Compatibility

Designed as a standard Class ZZ minus plug pin gage for use with compatible pin gage handles and holders sized for 0.381-inch diameter pins in precision inspection setups.

Installation Notes

Pin gages should be handled with clean cotton or lint-free gloves to prevent corrosion from skin contact. Insert the gage into the bore with light, even hand pressure only — never force a plug gage, as this can damage both the gage and the workpiece. Store gages in a protective case away from other metal tools to prevent nicking the gage surface. Periodic cleaning and light oiling per the manufacturer's storage guidelines will maintain dimensional integrity.