Spi 29-644-2 Class Zz Plus Plug Gage 0.644 in Dia

Product Description

The SPI 29-644-2 is a Class ZZ Plus plug gage designed for go/no-go inspection of internal bore diameters in precision machining and quality control applications. It measures a nominal diameter of 0.644 inches with a tolerance of 0.0002 inches, providing the close-tolerance verification required for checking drilled, reamed, or bored holes to specification. Constructed from steel, this gage is a standard working tool used by machinists, toolmakers, and quality technicians on the shop floor or in the inspection lab.

Class ZZ Plus plug gages are used in general-purpose dimensional inspection where tight tolerance control is required for production parts. This gage is suited for incoming inspection, in-process checks, and final acceptance testing of machined components. It is appropriate for use in job shops, production machining environments, and toolrooms where consistent bore diameter verification is part of the quality process.

Key Features

• 0.644 inch nominal measurement diameter for precise internal bore inspection
• 0.0002 inch tolerance for close-tolerance Class ZZ Plus classification
• Steel construction for durability and dimensional stability in shop environments
• Single-piece design suited for go/no-go pass-fail inspection routines
• Compact and lightweight at 0.2 pounds for easy bench or handheld use

Compatibility

Designed as an OEM-style replacement or direct-use Class ZZ Plus plug gage for applications requiring inspection of 0.644 inch nominal internal bore diameters per standard go/no-go gage practices.

Installation Notes

Plug gages are handled and used by machinists and quality control inspectors and do not require installation in the traditional sense. Before use, clean the gage and the bore being checked to remove chips, coolant, and debris that could affect the reading. Store the gage in its protective case or designated holder when not in use to prevent damage to the precision ground surface. Gage calibration and handling should follow applicable metrology standards for your facility.