Spi 29-872-9 Class Zz Plus Plug Gage 0.872 in Dia

Product Description

The SPI 29-872-9 is a Class ZZ Plus plug gage designed to verify the dimensional accuracy of bored, reamed, or machined holes with a nominal diameter of 0.872 inches. Manufactured from steel, it delivers a tolerance of 0.0002 inches, making it suitable for production inspection and quality-control applications where repeatable, reliable go/no-go measurement is required. Machinists, toolmakers, and quality technicians use plug gages like this one to confirm that hole dimensions fall within acceptable limits before parts advance to the next stage of production or assembly.

This gage is used in machine shops, manufacturing facilities, and precision fabrication environments. It is appropriate for inspecting holes in ferrous and non-ferrous workpieces produced by drilling, reaming, boring, or grinding operations. The Class ZZ tolerance class is standard for general-purpose inspection gaging in production settings. The compact size and 0.2-pound weight make it easy to handle at the machine or inspection station.

Key Features

• Nominal measurement diameter of 0.872 inches for direct hole verification
• Class ZZ Plus tolerance of 0.0002 inches for production-grade inspection accuracy
• Steel construction for durability and wear resistance in shop environments
• Lightweight at 0.2 pounds for easy single-hand use at the workpiece
• Go/no-go design enables fast pass-fail decisions without calculation

Compatibility

Designed as a standard Class ZZ Plus plug gage for general-purpose inspection of machined holes at 0.872 inches nominal diameter in production and quality-control applications.

Installation Notes

Plug gages are used by machinists and quality-control inspectors and require no permanent installation. Before use, clean the gage and the workpiece hole thoroughly to remove chips, coolant, and debris that could affect measurement accuracy. Never force a plug gage into a hole; apply only light, controlled pressure to avoid damaging the gage or altering the workpiece. Store the gage in its protective case and handle it with clean, dry hands or gloves to prevent corrosion and dimensional change from heat transfer.