Spi 29-429-8 Class Zz Plus Plug Gage 0.429 Inch

Product Description

The SPI 29-429-8 is a Class ZZ Plus plug gage designed to verify the acceptance of internal bore diameters at 0.429 inches. Machined from steel, this go/no-go style gage provides a tolerance of 0.0002 inches, making it a reliable tool for dimensional inspection in production and quality-control environments. Plug gages of this class are used where tighter-than-standard ZZ tolerances are required to confirm that drilled, reamed, or bored holes fall within specified limits. Machinists, toolroom technicians, and quality inspectors are the primary users of this instrument.

This gage is suited for inspection tasks in machine shops, manufacturing facilities, and precision fabrication operations. It is used to check hole diameters in metal workpieces where tight dimensional control is critical to assembly fit and function. Its compact form factor makes it practical for both bench inspection and inline production checks. At 0.429 inches nominal diameter, it addresses a common size range in general metalworking and precision machining applications.

Key Features

• Class ZZ Plus tolerance rating at 0.0002 inches for precise dimensional verification
• Nominal measurement diameter of 0.429 inches
• Steel construction for durability and dimensional stability
• Compact and lightweight at 0.2 pounds for easy bench or inline use
• Single-piece package quantity suitable for individual replacement or toolroom stocking

Compatibility

Designed as a direct-fit Class ZZ Plus plug gage for use in standard gage handle systems accepting 0.429 inch diameter gage members. Verify handle collet size range before installation.

Installation Notes

Plug gages should be handled with clean, dry hands or lint-free gloves to prevent corrosion from skin oils. Store in a protective case away from temperature extremes to maintain dimensional accuracy. Inspect the gage surface for nicks or burrs before each use, as surface damage will affect measurement validity. Calibration should be verified periodically against a traceable master to ensure ongoing accuracy.