Spi 19-731-9 Class Zz Minus Plug Pin Gage 0.731 in

Product Description

The SPI 19-731-9 is a Class ZZ minus plug pin gage used to verify hole diameters and bore tolerances in precision machining and fabrication work. With a nominal diameter of 0.731 inches and a tolerance of 0.0002 inches, this gage provides the accuracy required for go/no-go inspection routines. Class ZZ gages are the most commonly specified tolerance class for shop-floor dimensional inspection. The steel construction delivers the durability and wear resistance expected in production and maintenance environments. Machinists, toolmakers, and quality control technicians use pin gages like this one to confirm that drilled, reamed, or bored features meet print specifications before parts move to the next stage of production.

This plug pin gage is suited for use in machine shops, manufacturing facilities, and maintenance departments where hole diameter verification is part of a standard inspection process. The minus designation means the gage is ground to the low side of the nominal diameter, making it appropriate for checking minimum acceptable hole size in a go/no-go application. It is well-suited for use with steel, aluminum, and other common workpiece materials across a range of industries including general metalworking, automotive, and aerospace component inspection.

Key Features

• Nominal diameter of 0.731 inches for direct hole size verification
• Class ZZ tolerance class rated at plus or minus 0.0002 inches for shop-floor inspection accuracy
• Minus designation grounds the gage to the low side of nominal for go-type applications
• Steel construction provides wear resistance and dimensional stability during repeated use
• Lightweight at 0.2 pounds for easy single-hand operation during inspection

Compatibility

Designed as an OEM-style replacement or direct-use Class ZZ plug pin gage for standard bore and hole inspection applications requiring a 0.731-inch nominal diameter check.

Installation Notes

Pin gages are handled and used by machinists, toolmakers, and quality technicians and require no permanent installation. Clean the gage and the workpiece bore before use to prevent debris from affecting measurement accuracy. Store pin gages in a protective case away from moisture to prevent corrosion and dimensional drift. Do not force a pin gage into an undersized hole, as this can damage both the gage and the workpiece.