Spi 19-618-8 Class Zz Minus Plug Pin Gage 0.618 in

Product Description

The SPI 19-618-8 is a Class ZZ minus plug pin gage machined from steel, used to verify that a hole or bore meets its minimum acceptable diameter. At 0.618 inches nominal diameter with a minus tolerance of 0.0002 inches, this gage confirms whether a feature is at or above the lower limit of the tolerance band. Class ZZ gages are the standard working-grade choice for production inspection and incoming quality control on the shop floor. Machinists, tool and die makers, and quality technicians use minus plug gages to check that bored, drilled, or reamed holes have not been cut undersize.

This gage is suited to dimensional inspection tasks in manufacturing, machining, and fabrication environments where hole size verification is part of the production or receiving process. It is used to check bores in metal components across a range of industries including general machining, fluid power, and precision assembly. The single-ended design at 0.618 inches diameter makes it a direct go-gage for the lower boundary of a toleranced hole.

Key Features

• Class ZZ minus tolerance of 0.0002 inches for working-grade inspection accuracy
• 0.618 inches nominal diameter for direct lower-limit hole verification
• Steel construction for durability in production shop environments
• Single-gage format sized for straightforward go-gage application
• Compact and lightweight at 0.2 pounds for easy bench or floor use

Compatibility

Designed as a working-grade Class ZZ minus plug gage for dimensional inspection of 0.618-inch nominal diameter holes and bores in standard machining and manufacturing applications.

Installation Notes

Plug pin gages are installed and used by machinists, quality technicians, and inspection personnel — no special tooling is required beyond clean, burr-free hole preparation. Always clean the gage and the part bore before use to prevent contamination from affecting the reading. Do not force the gage into an undersized bore, as this can damage the gage surface and compromise accuracy. Store the gage in a protective case away from other tooling to prevent nicks or corrosion that would affect its calibrated diameter.