Spi 29-631-9 Class Zz Plus Plug Gage 0.631 in Steel

Product Description

The SPI 29-631-9 is a Class ZZ Plus plug gage designed to verify bore and hole diameters to a high degree of accuracy. The gage measures a nominal diameter of 0.631 inches with a tolerance of 0.0002 inches, providing the precise go/no-go reference required for quality control and inspection work. Constructed from steel, it is built to withstand repeated use in production and shop environments. Machinists, tool and die makers, and quality control inspectors rely on this type of gage to confirm that drilled, reamed, or bored features fall within specification before parts advance to assembly.

Class ZZ Plus plug gages are suited for general inspection tasks in manufacturing and machine shop settings. This gage is appropriate for checking through-holes and blind bores where dimensional conformance is required. It is used in both job-shop and production environments where go/no-go verification is part of an established quality process. The compact size and steel construction make it practical for bench inspection stations and in-process checks at the machine.

Key Features

• Nominal measurement diameter of 0.631 inches for precise bore verification
• Tolerance of 0.0002 inches meets Class ZZ Plus accuracy requirements
• Steel construction provides durability under repeated inspection use
• Go/no-go style gage supports fast pass-fail quality decisions
• Compact form factor suits bench inspection and in-process checks

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for inspection applications requiring a 0.631-inch nominal diameter Class ZZ Plus standard.

Installation Notes

Plug gages are handled and used by machinists and quality control technicians following standard metrology practices. Clean the gage and the bore being checked before use to avoid debris-related measurement error. Do not force the gage into an undersized bore, as this can damage the gage or the workpiece. Store the gage in its protective case when not in use to prevent wear and corrosion that would affect accuracy.