Spi 29-515-4 Class Zz Plus Plug Gage 0.515 in

Product Description

The SPI 29-515-4 is a Class ZZ Plus plug gage designed to verify the inside diameter of bored, drilled, or reamed holes to a nominal size of 0.515 inches. Built from steel, this go/no-go style inspection tool provides a tolerance of 0.0002 inches, making it suitable for precision quality-control work in machine shops, manufacturing facilities, and general metalworking environments. Machinists, tool-and-die technicians, and quality inspectors use plug gages like this one to confirm that finished holes fall within specified limits before parts advance to the next stage of production. The compact form factor and single-piece construction keep handling straightforward during high-volume inspection routines.

This gage is used in applications where hole diameter verification is required on ferrous and non-ferrous workpieces. Typical settings include job shops performing close-tolerance work, production lines running acceptance sampling, and inspection departments validating incoming or in-process parts. Class ZZ Plus gages are generally applied where commercial-grade tolerances are acceptable rather than the tighter limits demanded by Class X or Class Y tooling. The 0.515-inch nominal size addresses a common fractional and close-to-fractional bore range found in a wide range of mechanical assemblies.

Key Features

• 0.515-inch nominal diameter for precise hole inspection
• Class ZZ Plus tolerance classification suitable for commercial-grade inspection work
• 0.0002-inch tolerance for reliable go/no-go acceptance decisions
• Steel construction for durability in shop-floor environments
• Compact single-piece design simplifies handling during repetitive inspection tasks

Compatibility

Designed as an OEM-style inspection tool for verifying 0.515-inch nominal inside diameters in standard mechanical inspection and quality-control applications.

Installation Notes

Plug gages are handled and used by machinists, quality inspectors, and metrology technicians. Clean and lightly oil the gage before and after each use to prevent corrosion and ensure accurate readings. Never force the gage into a hole; entry should be smooth with light hand pressure only. Store in a protective case away from temperature extremes to maintain dimensional stability.