Spi 29-351-4 Class Zz Plus Plug Gage 0.351 in

Product Description

The SPI 29-351-4 is a Class ZZ Plus plug gage designed for go/no-go dimensional inspection of bored, drilled, or reamed holes. It measures a nominal diameter of 0.351 inches with a tolerance of 0.0002 inches, making it suitable for quality control applications where close-tolerance verification is required. Constructed from steel for durability and dimensional stability, this gage is a standard tool in machine shops, manufacturing floors, and production inspection stations where repeatable, accurate hole measurement is essential.

This plug gage is used in precision machining and fabrication environments to verify hole diameters to close tolerances. Class ZZ Plus gages are typically applied in less critical inspection tasks compared to Class Z or ZZ, but still deliver reliable dimensional verification for production-level quality checks. Machinists, quality control inspectors, and toolroom technicians use this type of gage as part of standard incoming or in-process inspection workflows.

Key Features

• Nominal measurement diameter of 0.351 inches for precise hole verification
• Tolerance of 0.0002 inches for reliable close-tolerance inspection
• Steel construction for wear resistance and long service life
• Class ZZ Plus designation suitable for production and general inspection use
• Compact and lightweight at 0.2 pounds for easy handling at the inspection station

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for any application requiring go/no-go inspection of 0.351-inch nominal diameter holes in production or toolroom environments.

Installation Notes

Plug gages should be handled by qualified machinists or quality control technicians familiar with gage use and care procedures. Before use, clean the gage and the hole being inspected to remove debris, oil, or burrs that could affect measurement accuracy. Do not force the gage into a hole; apply only light, consistent hand pressure to avoid gage wear or damage. Store gages in a protective case away from temperature extremes to maintain dimensional stability.