Spi 19-791-3 Class Zz Minus Plug Pin Gage 0.791 in

Product Description

The SPI 19-791-3 is a Class ZZ minus plug pin gage machined from steel and used to verify bore and hole diameters in precision inspection and quality control work. Designed to the minus tolerance convention, this gage measures 0.791 inches in nominal diameter with a tolerance of 0.0002 inches, providing a reliable go/no-go reference for dimensional verification. At 0.2 pounds, it is lightweight enough for repeated bench or floor-level use without fatigue. Machinists, toolroom inspectors, and quality technicians rely on Class ZZ pin gages as a cost-effective standard for production-floor inspection tasks.

Class ZZ plug gages are the most commonly specified tolerance class for general-purpose hole inspection in production environments. This gage is suited for verifying drilled, reamed, or bored holes in metal, plastic, and composite workpieces where dimensional conformance to engineering print is required. It fits standard inspection workflows at machine shops, fabrication facilities, and manufacturing lines where go/no-go verification is performed during or after machining operations.

Key Features

• Class ZZ tolerance class — the standard for general-purpose production inspection
• Minus tolerance design keeps the gage under nominal for conservative go/no-go evaluation
• 0.791 inches nominal diameter with 0.0002 inches tolerance for precise dimensional verification
• Steel construction provides durability and wear resistance in production environments
• Lightweight at 0.2 pounds for comfortable repeated handling

Compatibility

Designed as a general-purpose Class ZZ minus plug pin gage for verifying 0.791-inch nominal diameter holes and bores in standard production and quality inspection applications.

Installation Notes

Pin gages are handled and used by machinists, toolroom personnel, and quality inspectors — no installation is required. Store the gage in its protective sleeve or case when not in use to prevent surface damage and corrosion. Clean gaging surfaces with a lint-free cloth before each use to remove chips, oil, or debris that could affect measurement accuracy. Do not force the gage into a hole; a go gage should pass under its own weight or with light hand pressure only.