Spi 19-425-8 Class Zz Minus Plug Pin Gage 0.425 in

Product Description

The SPI 19-425-8 is a Class ZZ minus plug pin gage with a nominal diameter of 0.425 inches, manufactured from steel. It is used to verify hole diameters and bore tolerances in precision machining and inspection work. The minus designation means the gage is ground to the lower boundary of the Class ZZ tolerance band, with a tolerance of 0.0002 inches. Machinists, quality control technicians, and toolroom professionals use plug gages like this one to perform go/no-go checks and confirm that drilled, reamed, or bored features meet drawing specifications.

This pin gage is suited for inspection stations, toolrooms, and machine shop floor use where repeatable hole-size verification is required. Class ZZ is the most common tolerance class for general-purpose plug gages used in production environments. The 0.425-inch size covers a range of standard and close-tolerance bore applications found in metalworking, fabrication, and mechanical assembly operations.

Key Features

• Class ZZ minus tolerance classification for general-purpose hole inspection
• Nominal diameter of 0.425 inches for precise bore verification
• Tolerance of 0.0002 inches for repeatable measurement accuracy
• Steel construction for durability in shop floor environments
• Single-piece pin format for straightforward go/no-go inspection use

Compatibility

Designed as a general-purpose Class ZZ minus plug pin gage suitable for use with standard gage handle sets accepting 0.425-inch diameter pin gages in production and toolroom inspection applications.

Installation Notes

Plug pin gages are handled and used by machinists and quality control inspectors — no power source or trade licensing is required. Store the gage in a protective case away from other metal tooling to prevent nicks or surface damage that could affect measurement accuracy. Clean the gage and the bore being checked before use to remove chips, oil, or debris. Do not force the gage into a hole; if resistance is encountered, remove and inspect both the gage and the bore for burrs or contamination.