Spi 19-728-5 Class Zz Minus Plug Pin Gage 0.728 in

Product Description

The SPI 19-728-5 is a Class ZZ minus plug pin gage used to verify hole diameters and bore tolerances in precision machining and inspection work. It features a 0.728-inch nominal diameter and a minus tolerance of 0.0002 inches, confirming that a bored or reamed hole meets minimum acceptable size. The steel construction provides the hardness and wear resistance needed for repeated use in shop-floor and metrology-room environments. Machinists, tool and die makers, and quality control technicians use plug gages like this one to perform fast, reliable go/no-go functional checks without requiring a measuring instrument readout.

This gage is suited for use in manufacturing, machine shop, and inspection environments where hole size conformance must be verified to tight tolerances. It is appropriate for checking drilled, reamed, or bored holes in metal, plastic, and composite workpieces. The Class ZZ designation identifies this as a working gage intended for production inspection rather than master or reference gage applications. Its compact size and single-ended design make it easy to handle during high-volume part inspection.

Key Features

• Class ZZ minus tolerance rating for production-level go/no-go hole inspection
• 0.728-inch nominal diameter for direct bore verification at that size
• Minus tolerance of 0.0002 inches ensures the gage falls within the low side of the tolerance band
• Steel construction for durability and consistent dimensional stability during repeated use
• Single-piece plug design for straightforward, tool-free operation

Compatibility

Designed as a working-grade plug pin gage for production inspection of 0.728-inch nominal diameter holes in standard machining and quality assurance applications.

Installation Notes

Plug pin gages are handled and used by machinists and quality control personnel and do not require installation in the traditional sense. Before use, clean both the gage and the hole being checked to remove chips, coolant, and debris that could affect the reading. Never force the gage into a hole; apply only light hand pressure to avoid damage to the gage or the workpiece. Store the gage in a protective case away from temperature extremes to preserve dimensional accuracy.