Spi 29-842-2 Class Zz Plus Plug Gage 0.842 in

Product Description

The SPI 29-842-2 is a Class ZZ Plus plug gage designed for precision hole inspection in machining, manufacturing, and quality-control environments. It measures bore diameters at 0.842 inches with a tolerance of 0.0002 inches, making it suitable for go/no-go verification of close-tolerance bores. The gage is machined from steel for durability and dimensional stability under repeated use. Machinists, tool-and-die makers, and quality inspectors use plug gages like this one to confirm that drilled, reamed, or bored holes fall within specified dimensional limits before parts advance to assembly.

This plug gage is used in production and inspection settings where hole-diameter verification is required at 0.842 inches nominal. It is appropriate for both floor-level inspection at the machine and dedicated quality-control stations. Class ZZ Plus designation indicates the gage meets industry tolerance standards for workshop-grade plug gages used in general manufacturing inspection. The compact form factor and 0.2-pound weight make it easy to handle during repetitive inspection cycles.

Key Features

• 0.842-inch nominal diameter for direct bore verification at that size
• 0.0002-inch tolerance meets Class ZZ Plus gage-accuracy requirements
• Steel construction provides wear resistance and dimensional stability
• Lightweight at 0.2 pounds for comfortable single-hand use
• Go/no-go inspection method reduces operator subjectivity in pass-fail decisions

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for any application requiring inspection of 0.842-inch nominal diameter bores in steel, aluminum, or similar machinable materials.

Installation Notes

Plug gages should be handled with clean, dry hands or lint-free gloves to prevent corrosion and dimensional contamination. Before use, verify the gage surface is free of burrs, debris, or oil that could affect measurement accuracy. Store in a protective case away from temperature extremes to maintain calibration. Periodic recalibration against a master standard is recommended per your facility quality plan.