Spi 19-393-8 Class Zz Minus Plug Pin Gage 0.3930 in

Product Description

The SPI 19-393-8 is a Class ZZ minus plug pin gage designed for dimensional verification of bored holes, reamed bores, and machined features requiring precise go/no-go measurement. Built from steel, this pin gage measures a nominal diameter of 0.3930 inches with a tolerance of 0.0002 inches, placing it within the Class ZZ specification for general-purpose inspection use. At 0.2 pounds, it is a compact, hand-held instrument suited for use at the machine, on the inspection bench, or on the shop floor. Machinists, quality control technicians, and tool and die professionals rely on Class ZZ pin gages as a fast, reliable alternative to air gages or CMM measurement for routine bore checking.

This pin gage is appropriate for use in light manufacturing, precision machining, and quality inspection environments where bore diameter conformance must be verified quickly and repeatably. The minus designation indicates the gage is ground to the minus side of the nominal diameter, which is the standard configuration for a go-style plug gage application. It is well suited for incoming inspection, in-process control, and final verification of machined components in both job shop and production settings.

Key Features

• Nominal measurement diameter of 0.3930 inches for precise bore verification
• Class ZZ tolerance of 0.0002 inches, suitable for general-purpose inspection
• Minus designation provides go-gage fitment for conformance checking
• Steel construction for durability in shop floor environments
• Lightweight at 0.2 pounds for easy single-hand use

Compatibility

Designed as an OEM-style replacement or direct-use Class ZZ plug pin gage for any application requiring verification of a 0.3930-inch nominal bore diameter in steel-compatible inspection setups.

Installation Notes

Pin gages should be handled with clean, dry hands or cotton gloves to prevent corrosion from skin oils. Before use, verify the bore and gage surfaces are free of chips, coolant residue, and burrs that could cause a false reading or damage the gage. Store pin gages in their original case or a protective sleeve when not in use to maintain calibration integrity. Periodic recalibration against a traceable standard is recommended per your facility quality plan.