Spi 29-279-7 Class Zz Plus Plug Gage 0.279 in

Product Description

The SPI 29-279-7 is a Class ZZ Plus plug gage used to verify bore diameters in precision machining and inspection environments. It is ground to a nominal diameter of 0.279 inches with a tolerance of 0.0002 inches, placing it in the ZZ Plus accuracy class for go/no-go gauging applications. The gage body is constructed from steel for durability and dimensional stability under repeated use. Machinists, quality control technicians, and tool room professionals use plug gages like this one to confirm that drilled, reamed, or bored holes fall within specified limits.

This plug gage is suited for use in manufacturing inspection, machine shop quality control, and incoming material verification. It is appropriate for both job shop and production floor environments where consistent bore measurement at the 0.279-inch nominal size is required. The compact, single-ended design makes it easy to handle during high-volume inspection routines.

Key Features

• Nominal measurement diameter of 0.279 inches for precise bore verification
• Class ZZ Plus tolerance of 0.0002 inches for reliable go/no-go gauging
• Steel construction for dimensional stability and resistance to wear
• Compact form factor suited for bench and floor inspection use
• Single-piece packaging for individual replacement or supplemental gauging needs

Compatibility

Designed as an OEM-style replacement or supplemental plug gage for inspection setups requiring a 0.279-inch nominal bore diameter in Class ZZ Plus tolerance applications.

Installation Notes

Plug gages are handled and used by machinists and quality technicians — no permanent installation is required. Before use, clean the gage and the bore being inspected to remove chips, coolant, and debris that could affect measurement accuracy. Apply light gage oil when appropriate to reduce wear on the gage surface. Store the gage in a protective case away from temperature extremes to preserve dimensional accuracy.