Spi 29-068-4 Class Zz Plus Plug Gage 0.068 in

Product Description

The SPI 29-068-4 is a Class ZZ Plus plug gage used to verify bore and hole diameters in precision machining and quality control applications. It measures a nominal diameter of 0.068 inches with a tolerance of 0.0002 inches, making it suitable for tight-tolerance inspection work. The gage is constructed from steel for durability and dimensional stability during repeated use. Machinists, toolmakers, and quality technicians use plug gages like this to confirm whether a drilled or reamed hole falls within specified acceptance limits, functioning as a go or no-go reference tool in production and inspection settings.

This plug gage is intended for use in precision manufacturing environments where small-diameter hole verification is required. It is well suited for inspecting drilled, reamed, or punched holes in metal, plastic, and composite components. The Class ZZ Plus designation indicates it meets a defined accuracy standard appropriate for workshop-grade inspection and in-process gauging on production floors and in quality labs.

Key Features

• Nominal measurement diameter of 0.068 inches for small-bore inspection
• Tolerance of 0.0002 inches for precise acceptance verification
• Steel construction for dimensional stability and wear resistance
• Class ZZ Plus accuracy classification for workshop and production inspection
• Compact, single-piece design for easy handling during in-process checks

Compatibility

Designed as an OEM-style replacement and standard inspection tool for applications requiring plug gage verification of 0.068-inch nominal diameter holes in precision machining and quality control operations.

Installation Notes

Plug gages are typically handled and applied by machinists, toolmakers, or quality control technicians. Clean the gage and the hole being measured before use to avoid debris-related measurement errors. Do not force the gage into a hole; excessive insertion force can damage the gage or the workpiece and will produce unreliable readings. Store the gage in a protective case away from temperature extremes to preserve dimensional accuracy.