Spi 29-815-8 Class Zz Plus Plug Gage 0.815 in

Product Description

The SPI 29-815-8 is a Class ZZ Plus plug gage used to verify the inside diameter of machined holes to a 0.815-inch nominal size. It provides a tolerance of 0.0002 inches, meeting the requirements of Class ZZ Plus accuracy standards. The gage is constructed from steel for durability and dimensional stability under regular shop use. Machinists, quality control technicians, and toolroom professionals use plug gages like this one to confirm that drilled, bored, or reamed holes fall within specified tolerance ranges before parts move to the next stage of production.

This plug gage is suited for use in manufacturing, metalworking, and precision machining environments where hole size verification is required as part of in-process or final inspection. It is appropriate for both production floor checks and quality lab use. The 0.815-inch diameter size makes it applicable to components where medium-bore hole tolerancing is critical to assembly fit or function.

Key Features

• Class ZZ Plus accuracy rating for precise inside-diameter verification
• 0.815-inch nominal measurement diameter
• 0.0002-inch tolerance for tight conformance checking
• Steel construction for wear resistance and dimensional stability
• Compact form factor suitable for production floor and inspection bench use

Compatibility

Designed as a standard plug gage for verifying 0.815-inch nominal inside diameters in steel, aluminum, and other machined workpieces where Class ZZ Plus tolerance limits apply.

Installation Notes

Plug gages are handled and used by machinists and quality inspection personnel — no installation in the traditional sense is required. Before use, clean the gage and the hole being checked to remove chips, coolant, and debris that could affect measurement accuracy. Do not force the gage into the hole; if resistance is felt, the bore may be undersize and further machining may be needed. Store the gage in its case when not in use to protect the precision-ground surfaces from damage.