Spi 29-408-2 Class Zz Plus Plug Gage 0.408 Inch

Product Description

The SPI 29-408-2 is a Class ZZ Plus plug gage designed to verify inside diameters with a nominal measurement diameter of 0.408 inches and a tolerance of 0.0002 inches. Plug gages are go/no-go inspection tools used in precision machining and quality control environments to confirm that a drilled, reamed, or bored hole falls within an acceptable tolerance range. Constructed from steel, this gage provides the durability and dimensional stability required for repeated use in production or shop-floor inspection. Machinists, toolmakers, and quality control technicians are the primary users of this type of gage.

This plug gage is suited for use in machine shops, manufacturing facilities, and precision fabrication environments where tight bore tolerances must be verified. It is appropriate for both production inspection and incoming material verification. The Class ZZ Plus designation indicates a commercial-grade tolerance class commonly used for general-purpose inspection of holes and bores in metal, plastic, and composite workpieces. Its compact size makes it easy to handle during repetitive inspection tasks.

Key Features

• Nominal measurement diameter of 0.408 inches for precise bore verification
• Tolerance of 0.0002 inches meeting Class ZZ Plus specifications
• Steel construction for dimensional stability and wear resistance
• Go/no-go design streamlines pass/fail inspection decisions
• Compact and lightweight at 0.2 pounds for easy single-hand operation

Compatibility

Designed as a direct-use plug gage for inspecting bored, drilled, or reamed holes with a nominal diameter of 0.408 inches in general manufacturing and machine shop applications.

Installation Notes

Plug gages are handled by machinists and quality control technicians and do not require permanent installation. Before use, ensure the workpiece bore and the gage surface are clean and free of burrs, chips, or debris to prevent false readings and gage wear. Do not force the gage through a bore, as this can damage the gage surface and compromise measurement accuracy. Store the gage in its protective case when not in use to maintain calibration integrity.