Spi 19-998-4 Class Zz Minus Plug Pin Gage 0.998 in

Product Description

The SPI 19-998-4 is a Class ZZ minus plug pin gage with a nominal diameter of 0.998 inches and a tolerance of 0.0002 inches. Pin gages of this class are used to verify hole sizes and check dimensional conformance on machined parts. The Class ZZ designation indicates a general-purpose inspection grade suited for production and shop-floor measurement work. The minus designation means the gage is manufactured to the minus side of the tolerance, which is standard for plug gages used to check go or no-go conditions. Machinists, quality control technicians, and toolroom professionals use these gages as part of standard dimensional inspection routines.

This pin gage is appropriate for use in manufacturing environments where hole diameter verification is required. It fits into dimensional inspection workflows in machine shops, fabrication facilities, and quality control departments. The 0.998-inch diameter is a common nominal size used in precision mechanical assemblies and tooling applications. The steel construction provides the hardness and wear resistance needed for repeated contact with metal workpieces during inspection.

Key Features

• Class ZZ tolerance grade for general-purpose production inspection
• Minus designation for standard plug gage go or no-go application
• 0.0002-inch tolerance for consistent and repeatable dimensional checking
• Steel construction for durability and wear resistance in shop environments
• 0.998-inch nominal diameter for common precision hole inspection tasks

Compatibility

Designed as a standard Class ZZ minus plug pin gage for use in general production and inspection applications requiring verification of 0.998-inch nominal diameter holes.

Installation Notes

Pin gages should be handled with clean, dry hands or lint-free gloves to prevent corrosion from skin oils. Before use, ensure the gage and workpiece 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 apply a light coat of instrument oil periodically to prevent rust. Calibration should be verified against a traceable standard at regular intervals per your shop's quality management procedures.