Spi 19-777-2 Class Zz Minus Plug Pin Gage 0.777 in

Product Description

The SPI 19-777-2 is a Class ZZ minus plug pin gage machined to a 0.777 inch nominal diameter. It is used to verify that a drilled, reamed, or bored hole meets minimum dimensional tolerance. The gage is manufactured from steel and held to a tolerance of 0.0002 inches in the minus direction, meaning the gage is slightly undersize of the nominal dimension. Class ZZ is the standard tolerance grade for general-purpose inspection gaging in production and maintenance environments. Machinists, toolroom technicians, and quality control personnel use this gage to confirm hole size before assembly or final inspection.

This plug gage is suited for incoming inspection, in-process hole checking, and go/no-go verification workflows in machine shops, fabrication facilities, and maintenance departments. It fits standard gage handle sets and can be used as a standalone pin for quick manual checks. The 0.777 inch diameter makes it appropriate for applications requiring accurate verification of holes in that size range, including threaded inserts, bearing bores, and precision-fit fastener clearance holes.

Key Features

• Class ZZ tolerance grade for general-purpose production and maintenance inspection
• Minus designation confirms the gage is manufactured to the undersize side of nominal
• 0.0002 inch tolerance provides reliable, repeatable hole verification
• Steel construction for durability and dimensional stability under normal shop conditions
• Compatible with standard plug gage handles for convenient single-hand use

Compatibility

Designed as an OEM-style Class ZZ minus plug pin gage for use with standard gage handle sets accommodating 0.777 inch diameter gage members.

Installation Notes

Plug pin gages are handled and stored by quality control and toolroom personnel following standard metrology practices. Clean and lightly oil the gage before and after use to prevent corrosion and maintain dimensional accuracy. Do not force the gage into an undersized hole, as this can damage both the gage and the workpiece. Store in a protective case away from temperature extremes to preserve calibration integrity.