Spi 29-441-3 Class Zz Plus Plug Gage 0.441 in

Product Description

The SPI 29-441-3 is a Class ZZ Plus plug gage machined to a nominal diameter of 0.441 inches with a tolerance of 0.0002 inches. Plug gages in this class are used to verify that a drilled, reamed, or bored hole meets a specified diameter within controlled tolerance limits. The steel construction provides durability and dimensional stability across repeated use cycles. This gage is a go-type or no-go-type dimensional inspection tool used by machinists, quality control technicians, and tool-and-die professionals to confirm conformance on production parts.

This plug gage is suited for inspection operations in machine shops, manufacturing facilities, and job shops where hole diameter verification is a routine part of the quality process. It is appropriate for use on mild steel, aluminum, brass, and other common workpiece materials where a 0.441-inch nominal diameter is the specified feature. The Class ZZ Plus designation indicates a tighter manufacturing tolerance on the gage itself compared to standard Class ZZ gages, making it well-suited for applications requiring closer dimensional control.

Key Features

• Nominal measurement diameter of 0.441 inches for direct hole inspection
• Class ZZ Plus tolerance of 0.0002 inches provides reliable dimensional verification
• Steel construction for wear resistance and long service life
• Single-piece gage format suited for bench inspection or in-process checks
• Compact and lightweight at 0.2 pounds for easy handling

Compatibility

Designed as a direct-fit Class ZZ Plus plug gage for inspection of holes with a nominal diameter of 0.441 inches in standard machining and quality control applications.

Installation Notes

Plug gages are handled and used by quality technicians and machinists following standard metrology practices. Before use, clean both the gage and the workpiece bore to remove chips, coolant, or debris that could affect measurement accuracy. Apply light gage oil if required by your shop procedure to reduce wear on the gage surface. Store in a protective case away from impact and temperature extremes to maintain calibration integrity.