Spi 19-685-7 Class Zz Minus Plug Pin Gage 0.685 in

Product Description

The SPI 19-685-7 is a Class ZZ minus plug pin gage with a nominal diameter of 0.685 inches, manufactured from steel. Plug pin gages are precision go/no-go inspection tools used to verify bore and hole diameters to a defined tolerance. This gage carries a minus tolerance of 0.0002 inches, meaning its actual diameter is ground undersized from nominal within that tolerance band. It is used primarily in machine shops, quality control labs, and manufacturing environments where dimensional verification of drilled, reamed, or bored holes is required. Machinists, quality technicians, and tool-and-die professionals are the typical users.

Class ZZ is the working-grade classification for plug gages, suitable for general production inspection where high-volume use is expected. This 0.685-inch gage fits applications requiring verification of holes in that diameter range across metals, plastics, and other machinable materials. It is appropriate for use in both job-shop and production floor environments where consistent bore acceptance criteria must be maintained.

Key Features

• Nominal diameter of 0.685 inches for direct hole verification in that size range
• Class ZZ minus tolerance of 0.0002 inches ground undersized from nominal
• Steel construction for durability and dimensional stability under repeated use
• Single-piece plug gage format for straightforward go/no-go inspection workflow
• Compact and lightweight at 0.2 pounds for easy bench or handheld use

Compatibility

Designed as an OEM-style working gage for use in standard plug gage handles or holders sized for 0.685-inch diameter gage members, consistent with common Class ZZ minus plug gage tooling setups.

Installation Notes

Plug pin gages should be handled with clean, dry hands or cotton gloves to prevent corrosion from skin oils affecting dimensional accuracy. Store in a protective case away from other tooling to prevent contact damage to the ground surface. Periodically verify the gage against a calibrated master or send out for recalibration according to your facility quality plan. Class ZZ gages are working gages and are not intended for use as masters or reference standards.