Spi 29-377-9 Class Zz Plus Plug Gage 0.377 in

Product Description

The SPI 29-377-9 is a Class ZZ Plus plug gage designed for go/no-go dimensional inspection of bored, drilled, and reamed holes with a nominal diameter of 0.377 inches. Manufactured from steel, it holds a tolerance of 0.0002 inches, making it suitable for verifying hole size compliance in production and inspection environments. Class ZZ is the standard tolerance class for general-purpose plug gages used in shop-floor and quality-control applications. Machinists, tool-and-die makers, and quality technicians use this type of gage to confirm that a finished hole falls within the acceptable size range before assembly or further machining.

This plug gage is used in metal fabrication shops, machine shops, and manufacturing facilities wherever hole diameter must be verified to a tight tolerance. It is appropriate for checking holes in ferrous and non-ferrous workpieces where a 0.377-inch nominal diameter is specified. The 0.0002-inch tolerance class makes it well suited for inspection work that demands consistent, repeatable measurement results on moderate-precision components.

Key Features

• Class ZZ Plus tolerance rating for general-purpose shop and inspection use
• 0.377-inch nominal measurement diameter for direct hole verification
• 0.0002-inch tolerance provides reliable go/no-go discrimination
• Steel construction for durability in production environments
• Compact, lightweight design at 0.2 pounds for easy single-hand use

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for any application requiring a Class ZZ general-purpose go/no-go gage at 0.377 inches nominal diameter.

Installation Notes

Plug gages are used by machinists and quality inspectors and require no installation in the traditional sense, but proper handling practice is essential to maintain gage accuracy. Always clean and deburr the hole before gaging to avoid false readings or gage damage. Store the gage in a protective case away from other metal tools to prevent nicks or corrosion on the gage surface. Calibration should be verified periodically against a traceable standard in accordance with your quality system requirements.