Spi 19-866-3 Class Zz Minus Plug Pin Gage 0.866 in

Product Description

The SPI 19-866-3 is a Class ZZ minus plug pin gage machined from steel, designed to check the minimum acceptable size of a hole or bore during inspection and quality-control work. The gage measures 0.866 inches in diameter and carries a tolerance of 0.0002 inches, conforming to Class ZZ minus specifications for go/no-go dimensional verification. At 0.2 pounds, it is a compact, single-piece instrument suited for bench inspection, in-process checks on the shop floor, and receiving inspection. Machinists, toolmakers, quality technicians, and precision fabricators are the primary users.

Class ZZ minus plug gages are used in light manufacturing, machine shops, and fabrication environments where hole-size verification is required against a dimensional standard. The minus designation means the gage is manufactured below nominal, making it appropriate for checking minimum material condition. This gage is suited for use with ferrous and non-ferrous workpieces where a 0.866-inch nominal bore must be confirmed within tolerance before assembly or further processing.

Key Features

• Class ZZ minus classification for minimum material condition hole verification
• 0.866-inch nominal diameter for direct bore and hole inspection
• 0.0002-inch tolerance conforming to Class ZZ gage standards
• Steel construction for durability and dimensional stability
• Lightweight at 0.2 pounds for easy single-hand use at the bench or machine

Compatibility

Designed as a direct-use Class ZZ minus plug gage for any application requiring 0.866-inch nominal bore inspection in accordance with standard go/no-go gage practices.

Installation Notes

Plug pin gages are handled and used by machinists and quality technicians — no installation trade license is required, but proper gage handling practice applies. Store the gage in a protective case away from chips, coolant, and temperature extremes to preserve dimensional accuracy. Clean the gage and the bore being checked before use to prevent debris from affecting the measurement result. Never force a plug gage into a hole; if resistance is felt, the bore is undersize and forcing the gage risks damage to both the gage and the workpiece.