Spi 29-380-3 Class Zz Plus Plug Gage 0.38 Inch

Product Description

The SPI 29-380-3 is a Class ZZ Plus plug gage designed to verify bore and hole diameters with high accuracy in machining, quality control, and inspection applications. It measures a nominal diameter of 0.38 inches with a tolerance of 0.0002 inches, making it suitable for go/no-go inspection work where tight dimensional control is required. Constructed from steel for durability and wear resistance, this plug gage is a standard hand tool used by machinists, quality technicians, and tool-and-die professionals. Its compact size and light weight make it easy to handle during high-volume inspection routines.

This plug gage is used in shop floor and laboratory environments where bore diameter verification is part of a standard inspection process. It is well suited for checking drilled, reamed, or bored holes in metal and plastic workpieces. Typical applications include incoming inspection, in-process quality checks, and final part verification in manufacturing and fabrication settings. The Class ZZ Plus classification indicates a specific tolerance grade appropriate for general-purpose inspection work.

Key Features

• Nominal measurement diameter of 0.38 inches for precise bore inspection
• Tolerance of 0.0002 inches meets Class ZZ Plus grade requirements
• Steel construction provides wear resistance and dimensional stability
• Lightweight at 0.2 pounds for comfortable single-hand use
• Suitable for go/no-go inspection routines in production environments

Compatibility

Designed as a standard Class ZZ Plus plug gage for general-purpose bore and hole diameter inspection at 0.38 inches nominal diameter. Compatible with standard gage handle holders sized for this diameter range.

Installation Notes

Plug gages are handled and used by quality control technicians and machinists and do not require power tools or installation in a fixed system. Keep the gage clean and lightly oiled when not in use to prevent corrosion and maintain accuracy. Do not force the gage into a hole that is undersized, as this can damage the gage surface and affect calibration. Periodic recalibration against a certified reference standard is recommended to maintain measurement traceability.