Spi 29-624-4 Class Zz Plus Plug Gage 0.624 in Dia

Product Description

The SPI 29-624-4 is a Class ZZ Plus plug gage designed to verify bore and hole diameters to a nominal size of 0.624 inches. Built from steel, it delivers a dimensional tolerance of 0.0002 inches, making it suitable for go/no-go inspection work on production floors, in machine shops, and in field quality-control applications. Machinists, quality inspectors, and tool-and-die professionals use plug gages like this one to confirm that drilled, reamed, or bored features meet print specifications before parts advance to the next stage of assembly or shipment.

This gage is suited for single-point diameter verification in manufacturing and inspection environments where consistent, repeatable measurement of 0.624-inch nominal bores is required. It is appropriate for use on steel, aluminum, plastic, and other workpiece materials where bore acceptance or rejection must be confirmed quickly and reliably. The Class ZZ Plus classification indicates a commercial-grade tolerance level commonly used for production inspection rather than master or reference gage applications.

Key Features

• Nominal diameter of 0.624 inches for precise bore verification
• Tolerance of 0.0002 inches (0.0051 mm) for reliable go/no-go inspection
• Class ZZ Plus classification — standard production inspection grade
• Steel construction for durability and dimensional stability
• Compact and lightweight at 0.2 pounds for easy bench or field use

Compatibility

Designed as a direct-use plug gage for any application requiring verification of a 0.624-inch nominal bore diameter in standard production or inspection workflows.

Installation Notes

Plug gages are handled and used by machinists and quality inspection personnel following standard metrology practices. Store the gage in a clean, dry location away from temperature extremes to prevent thermal expansion errors. Clean the gage and the bore being measured before use to avoid false readings caused by chips or debris. Apply light, consistent insertion force only — forcing a plug gage can damage both the gage and the workpiece bore.