Spi 29-168-2 Class Zz Plus Plug Gage 0.168 in Dia

Product Description

The SPI 29-168-2 is a Class ZZ Plus plug gage used to verify the diameter of machined holes and bores to a nominal size of 0.168 inches. It checks whether a hole falls within acceptable tolerance limits, making it a standard tool for dimensional inspection in machining, fabrication, and quality control environments. The gage holds a tolerance of 0.0002 inches (0.0002 mm), placing it in the ZZ Plus accuracy class suited for general-purpose inspection work. Constructed from steel for wear resistance and dimensional stability, it is used by machinists, tool and die makers, and quality inspectors on the shop floor or in the inspection lab.

This plug gage is used in manufacturing and fabrication settings where hole size verification is required before assembly or final inspection. It is well suited for checking drilled, reamed, or bored holes in metal components. The 0.168-inch nominal size targets small-diameter features common in precision mechanical assemblies. This gage is handled by machinists, QC technicians, and production inspectors working to tight dimensional requirements in job shops, production facilities, and inspection departments.

Key Features

• Nominal measurement diameter of 0.168 inches for small-bore inspection
• Class ZZ Plus tolerance of 0.0002 inches for general-purpose dimensional verification
• Steel construction for durability and dimensional stability under repeated use
• Go/No-Go style inspection tool for fast pass-fail hole checking
• Compact single-piece design suited for shop floor and inspection lab use

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for general-purpose inspection of 0.168-inch nominal diameter holes in machined metal components.

Installation Notes

Plug gages are handled by qualified machinists or quality control technicians and do not require installation in the traditional sense. Before use, clean the gage and the workpiece bore to remove chips, coolant, and debris that could affect measurement accuracy. Apply light gaging pressure only — forcing a plug gage can damage both the gage and the part. Store the gage in its case when not in use to protect the precision ground surface from nicks and corrosion.