Spi 29-684-8 Class Zz Plus Plug Gage 0.684 in Dia

Product Description

The SPI 29-684-8 is a Class ZZ Plus plug gage designed to verify inside diameter dimensions to a nominal size of 0.684 inches. Built from steel, this go/no-go style gage checks bore conformance with a tolerance of 0.0002 inches, making it suitable for precision inspection work in machine shops, manufacturing facilities, and maintenance environments. Machinists, quality control technicians, and toolroom professionals use plug gages like this one to confirm that drilled, reamed, or bored holes meet dimensional specifications before assembly or final inspection sign-off.

Class ZZ Plus plug gages are appropriate for general-purpose inspection of production and toolroom bores. This gage is suited for use on ferrous and non-ferrous workpieces where inside diameter verification is required. The 0.684-inch nominal size targets a common bore dimension found across a range of mechanical components. Its compact, single-piece form makes it easy to handle and store in a standard gage stand or case.

Key Features

• Nominal measurement diameter of 0.684 inches for precise bore verification
• Class ZZ Plus tolerance of 0.0002 inches meets general-purpose inspection standards
• Steel construction provides durability and wear resistance in shop environments
• Compact, lightweight design at 0.2 pounds for easy single-hand use
• Single-piece plug gage format for straightforward pass/fail dimensional checks

Compatibility

Designed as a general-purpose Class ZZ Plus plug gage for verifying 0.684-inch nominal inside diameter bores in standard machining and quality inspection applications.

Installation Notes

Plug gages are handled and used by machinists and quality technicians following standard metrology practices. Before use, clean the gage and bore surfaces to remove chips, coolant, and debris that could affect measurement accuracy. Do not force the gage into an undersize bore, as this can damage the gage surface and compromise calibration. Store the gage in a protective case away from other tooling to prevent wear or impact damage.