Spi 29-656-6 Class Zz Plus Plug Gage 0.656 in Dia

Product Description

The SPI 29-656-6 is a Class ZZ Plus plug gage used to verify the inside diameter of precision-machined holes to a nominal size of 0.656 inches. Built from steel, this go/no-go style gage delivers a tolerance of 0.0002 inches, making it suitable for quality control checks in production and inspection environments. Machinists, toolmakers, and quality technicians use plug gages like this to confirm that bored, drilled, or reamed holes fall within specified dimensional limits before parts move to the next stage of assembly or finishing.

This gage is appropriate for use in machine shops, manufacturing facilities, and precision fabrication environments where hole diameter verification is part of a standard inspection process. At 0.656 inches nominal diameter with a steel construction, the 29-656-6 is sized for mid-range bore applications. It is typically used in conjunction with a gage handle or collet-style holder suited to its diameter. Class ZZ Plus gages are generally used for production inspection rather than master or laboratory-grade work.

Key Features

• Nominal measurement diameter of 0.656 inches for precise bore verification
• Tolerance of 0.0002 inches meets Class ZZ Plus classification standards
• Steel construction for durability in repeated production use
• Compact and lightweight at 0.2 pounds for easy handling during inspection
• Single-piece package quantity suits individual tool crib or bench use

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for any application requiring Class ZZ Plus bore inspection at a 0.656-inch nominal diameter. Compatible with standard gage handles and holders sized for this diameter range.

Installation Notes

Plug gages should be handled by qualified inspection personnel or machinists familiar with gage use and care. Clean the gage and the bore being measured before use to prevent debris from affecting readings or causing wear. Store the gage in a protective case or sleeve when not in use to preserve the lapped surface finish. Do not force the gage into an undersized hole, as this can damage the gage face and compromise accuracy.