Spi 29-445-4 Class Zz Plus Plug Gage 0.445 in

Product Description

The SPI 29-445-4 is a Class ZZ Plus plug gage designed to verify the dimensional accuracy of machined holes and bores. Built from steel, this go/no-go style inspection tool checks whether a hole diameter conforms to its specified tolerance. The 29-445-4 measures a nominal diameter of 0.445 inches and holds a tolerance of 0.0002 inches, making it suitable for moderate-precision inspection work on production floors, in machine shops, and in quality-control environments. Machinists, toolmakers, and QC inspectors use plug gages like this to confirm that drilled, reamed, or bored holes fall within acceptable dimensional limits before parts proceed to assembly.

This plug gage is intended for use in general industrial and manufacturing settings where hole diameter verification is part of a standard inspection process. Class ZZ Plus gages are commonly applied to production-volume inspection of through-holes and blind holes in metal and plastic components. The compact size and light weight of 0.2 pounds make it easy to handle during repetitive inspection cycles on the shop floor or at a dedicated inspection station.

Key Features

• Nominal measurement diameter of 0.445 inches for precise hole inspection
• Tolerance of 0.0002 inches supports moderate-precision dimensional verification
• Class ZZ Plus designation indicates conformance to recognized plug gage classification standards
• Steel construction for durability under repeated use in production environments
• Lightweight at 0.2 pounds for comfortable handling during high-volume inspection

Compatibility

Designed as an OEM-style replacement or direct addition to standard plug gage sets used for hole diameter inspection in general machining and manufacturing quality-control applications.

Installation Notes

Plug gages are handled by machinists, toolmakers, and quality-control technicians as part of dimensional inspection procedures. Before use, ensure the gage and the workpiece are at the same temperature to avoid measurement error caused by thermal expansion. Keep the gage clean and lightly oiled when stored to prevent corrosion of the steel surfaces. Do not force the gage into a hole, as this can damage the gage or the workpiece and compromise measurement integrity.