Spi 29-530-3 Class Zz Plus Plug Gage 0.53 in Steel

Product Description

The SPI 29-530-3 is a Class ZZ Plus plug gage designed for go/no-go dimensional inspection of bored or drilled holes with a nominal diameter of 0.53 inches. Manufactured from steel, this gage holds a tolerance of 0.0002 inches, making it suitable for verifying hole size conformance in production and quality-control environments. Class ZZ Plus gages meet industry standards for working gages used in general-purpose inspection, where consistent, repeatable measurement is required. Machinists, tool-and-die makers, and quality technicians use plug gages like this as a fast, reliable method for pass/fail hole verification without the need for variable measurement instruments.

This plug gage is appropriate for use in machine shops, manufacturing facilities, and maintenance environments where hole diameter verification is part of a standard inspection routine. It is suited for inspecting holes produced by drilling, reaming, or boring operations. The 0.53-inch nominal diameter and tight 0.0002-inch tolerance make it a practical choice for medium-precision production work where dimensional consistency is critical to assembly or function.

Key Features

• Class ZZ Plus tolerance rating for general-purpose go/no-go hole inspection
• Nominal diameter of 0.53 inches for accurate hole size verification
• Tolerance of 0.0002 inches for consistent, repeatable pass/fail results
• Steel construction for durability in shop and production environments
• Compact and lightweight at 0.2 pounds for easy handling during inspection

Compatibility

Designed as an OEM-style working gage for general-purpose hole inspection of 0.53-inch nominal diameter bores in production and quality-control applications.

Installation Notes

Plug gages are handled and used by machinists, quality technicians, and inspection personnel — no power tools or trade licensing is required for standard use. Clean the gage and the hole being checked before use to prevent debris from affecting measurement accuracy. Store the gage in a protective case when not in use to prevent damage to the precision-ground surfaces. Periodically verify gage calibration against a certified master to maintain measurement integrity over time.