Spi 29-628-5 Class Zz Plus Plug Gage 0.628 in

Product Description

The SPI 29-628-5 is a Class ZZ Plus plug gage machined to a nominal diameter of 0.628 inches with a tolerance of 0.0002 inches (0.0051 mm). Plug gages of this class are go/no-go inspection tools used to verify that bored, drilled, or reamed holes fall within a specified dimensional range. The 29-628-5 is constructed from steel for wear resistance and dimensional stability during repeated use. Machinists, tool-and-die technicians, and quality-control inspectors use Class ZZ Plus gages for production inspection of medium-tolerance holes where a controlled fit must be confirmed quickly and reliably.

Class ZZ Plus plug gages are suited to general-purpose production inspection in machine shops, manufacturing facilities, and job-shop environments. This gage is intended for verifying hole diameters in ferrous and non-ferrous workpieces during in-process or final inspection. Its compact form factor makes it practical for both bench inspection and floor-level use. The 0.628-inch nominal diameter covers common bore sizes found in mid-tolerance mechanical assemblies.

Key Features

• Nominal diameter of 0.628 inches for direct hole inspection at that target bore size
• Class ZZ Plus tolerance of 0.0002 inches (0.0051 mm) for reliable go/no-go gauging
• Steel construction provides durability and dimensional stability under frequent use
• Compact, lightweight design at 0.2 pounds for easy handling at the inspection bench or production floor
• Single-piece package quantity suitable for individual technician or tool-crib use

Compatibility

Designed as an OEM-style inspection tool for general-purpose hole gauging applications requiring a 0.628-inch nominal diameter at Class ZZ Plus accuracy.

Installation Notes

Plug gages are handled and used by machinists or quality-control technicians, not installed in a system. Before use, clean both the gage and the workpiece bore with a lint-free cloth to remove chips, coolant, and debris that could affect the reading. Apply light gage oil to the gage surface to reduce wear and prevent corrosion during storage. Store the gage in its protective case when not in use to maintain dimensional accuracy and prevent damage to the precision ground surface.