Spi 29-501-4 Class Zz Plus Plug Gage 0.501 Inch

Product Description

The SPI 29-501-4 is a Class ZZ Plus plug gage used to verify the inside diameter of bored, drilled, or reamed holes to a nominal size of 0.501 inches. It holds a tolerance of 0.0002 inches, making it suitable for go/no-go inspection workflows where precise dimensional verification is required. Constructed from steel, this gage is handled by machinists, toolroom inspectors, and quality control technicians in manufacturing and precision metalworking environments. Class ZZ is the standard tolerance class for general-purpose inspection of production parts.

This plug gage is used in shop-floor and inspection-room applications where hole diameter acceptance must be confirmed before assembly or further machining. It applies to residential and commercial manufacturing settings where tight tolerances govern part fit and function. Typical scenarios include incoming inspection, in-process quality checks, and final acceptance testing of machined components requiring a 0.501-inch bore.

Key Features

• Nominal measurement diameter of 0.501 inches for precise hole inspection
• Class ZZ Plus tolerance of 0.0002 inches for general-purpose go/no-go gauging
• Steel construction for durability and dimensional stability in shop environments
• Lightweight at 0.2 pounds for easy single-handed handling during inspection
• Individual unit packaging supports single-piece inspection and toolroom use

Compatibility

Designed as a general-purpose Class ZZ plug gage for verifying 0.501-inch diameter bores in machined components across standard production and inspection applications.

Installation Notes

Plug gages are handled by quality technicians or machinists and require no power source or mounting. Keep the gage clean and lightly oiled when not in use to prevent corrosion and maintain dimensional accuracy. Do not force the gage into a bore; resistance indicates the hole is undersize and requires additional machining. Store separately from cutting tools to avoid surface damage that could affect measurement reliability.