Spi 29-495-9 Class Zz Plus Plug Gage 0.495 in Dia

Product Description

The SPI 29-495-9 is a Class ZZ Plus plug gage machined to a nominal diameter of 0.495 inches with a tolerance of 0.0002 inches. Plug gages of this class are used to verify that a drilled, reamed, or bored hole falls within a specified dimensional limit. The go or no-go inspection method relies on the gage either passing through or being rejected by the hole, giving a fast pass-fail result without measurement calculation. Constructed from steel, the 29-495-9 is suited to shop-floor and inspection-room use wherever hole-diameter verification is part of a quality or production process.

This gage is appropriate for precision machining environments, tool-and-die shops, and production facilities that require dimensional verification of holes at or near the 0.495-inch nominal size. It is typically used by machinists, quality-control inspectors, and tool-room technicians checking finished or in-process parts against engineering print tolerances. The Class ZZ Plus rating designates a specific tolerance grade appropriate for inspection and acceptance gaging of commercial-tolerance work.

Key Features

• Nominal measurement diameter of 0.495 inches for direct hole-size verification
• Class ZZ Plus tolerance grade at 0.0002 inches for reliable pass-fail inspection
• Steel construction provides wear resistance for repeated shop-floor use
• Compact and lightweight at 0.2 pounds for easy single-hand handling
• Single-piece quantity packaging supports individual replacement or inventory stocking

Compatibility

Designed as an OEM-style replacement or direct substitute for Class ZZ Plus plug gages measuring a 0.495-inch nominal bore diameter in standard machining and inspection applications.

Installation Notes

Plug gages are hand tools and require no permanent installation. Before use, clean the gage and the bore being checked to remove chips, coolant, or debris that could affect the reading. Apply light gaging oil when checking ferrous materials to reduce wear on the gage surface. Store the gage in a protective case away from other tooling to prevent nicks or corrosion that would compromise dimensional accuracy.