Spi 29-054-4 Class Zz Plus Plug Gage 0.054 in

Product Description

The SPI 29-054-4 is a Class ZZ Plus plug gage machined from steel and used to verify bore and hole diameters to a nominal size of 0.054 inches. It holds a tolerance of 0.0002 inches, making it suited for inspection of precision-machined components where tight dimensional control is required. Class ZZ Plus designates a tolerance grade appropriate for general-purpose production inspection. Machinists, tool-and-die makers, and quality-control technicians use plug gages like this one to confirm whether a drilled, reamed, or bored hole falls within specified dimensional limits.

This gage is applied in machine shops, manufacturing facilities, and precision fabrication environments where small-diameter bore inspection is part of routine quality assurance. Its compact size and steel construction make it practical for bench inspection and inline production checks. The 0.054-inch nominal diameter targets fine bores typical in hydraulic fittings, instrument components, and close-tolerance mechanical assemblies. Individual unit packaging suits single-station inspection setups.

Key Features

• Nominal diameter of 0.054 inches for small-bore inspection
• Class ZZ Plus tolerance grade at 0.0002 inches for production-level accuracy
• Steel construction for durability and dimensional stability
• Single-piece unit suitable for bench or inline inspection use

Compatibility

Designed as a general-purpose plug gage for verifying small bores and drilled holes at a nominal diameter of 0.054 inches in standard production inspection applications.

Installation Notes

Plug gages are handled and used by machinists and quality-control inspectors. Before use, clean the gage and the bore being checked to remove chips, coolant, and debris that could affect measurement. Apply light gaging force only — never force a plug gage into a hole. Store the gage in its protective case when not in use to prevent surface damage that would affect accuracy.