Spi 29-999-0 Class Zz Plus Plug Gage 0.999 Inch

Product Description

The SPI 29-999-0 is a Class ZZ Plus plug gage used to verify bore and hole diameters to a precise nominal size of 0.999 inches. Built from steel, this go/no-go style gage is a standard dimensional inspection tool used by machinists, quality control technicians, and tool-and-die professionals. It holds a tolerance of 0.0002 inches, making it suitable for medium-precision inspection work where consistent, repeatable measurements are required on production floors or in shop environments.

This plug gage is used in manufacturing, machining, and metrology applications where hole diameter conformance must be verified against a fixed nominal size. Class ZZ gages are commonly applied in general-purpose inspection of drilled, reamed, or bored holes in steel, aluminum, and other machinable materials. The compact form factor and single-piece construction make it straightforward to use with standard gage handle setups.

Key Features

• Nominal diameter of 0.999 inches for direct go/no-go bore inspection
• Class ZZ Plus tolerance of 0.0002 inches for repeatable medium-precision measurement
• Steel construction for durability and dimensional stability in shop use
• Compact and lightweight at 0.2 pounds for easy one-hand handling
• Compatible with standard plug gage handles for flexible setup

Compatibility

Designed as a direct-fit replacement or standard-issue Class ZZ Plus plug gage for any application requiring inspection of a 0.999 inch nominal bore diameter using a conventional gage handle.

Installation Notes

Plug gages are installed and used by machinists and quality control inspectors and do not require electrical isolation or fluid shutoff. Clean the gage and the bore to be measured before use to prevent false readings caused by debris or coolant residue. Do not force the gage through an undersized bore, as this can damage the gage surface and alter its calibration. Periodic recalibration against a certified master reference is recommended to maintain measurement accuracy.