Spi 29-518-8 Class Zz Plus Plug Gage 0.518 in

Product Description

The SPI 29-518-8 is a Class ZZ Plus plug gage designed for go/no-go inspection of 0.518-inch diameter bores and holes. It provides a reliable, hand-held method for verifying that a machined or drilled hole meets the specified dimensional tolerance. The gage is manufactured from steel for durability and dimensional stability under repeated use. With a tolerance of 0.0002 inches, this gage is suited for quality control work in machine shops, manufacturing facilities, and maintenance environments where tight bore tolerances must be confirmed quickly and accurately.

Plug gages of this type are used in production inspection and incoming quality control wherever hole diameter must be verified to close tolerances. The 29-518-8 is appropriate for checking bores in machined components, fixtures, tooling blocks, and similar metal or hard-material parts. It is a standard tool in machine shops and metrology departments handling work that requires repeatable, traceable dimensional verification. Class ZZ Plus designation indicates it meets the tolerance class associated with production-level go/no-go inspection work.

Key Features

• 0.518-inch nominal diameter for direct bore inspection
• Class ZZ Plus tolerance class for production go/no-go inspection
• 0.0002-inch tolerance for close-tolerance bore verification
• Steel construction for dimensional stability and wear resistance
• Compact, hand-held form factor for fast in-process checks

Compatibility

Designed as an OEM-style replacement or direct substitute for Class ZZ Plus plug gages measuring 0.518-inch diameter bores in production inspection and quality control applications.

Installation Notes

Plug gages are handled and used by machinists, quality technicians, and inspection personnel. Before use, clean both the gage and the bore to remove chips, coolant, or debris that could affect the reading. Allow the gage and workpiece to stabilize to the same ambient temperature to avoid thermal expansion errors. Do not force the gage into the bore, as this can damage the gage surface and produce false readings.