Spi 19-394-6 Class Zz Minus Plug Pin Gage 0.394 in

Product Description

The SPI 19-394-6 is a Class ZZ minus plug pin gage used to verify the diameter of machined holes to close dimensional tolerances. It measures 0.394 inches in diameter and holds a tolerance of 0.000200 inches, making it appropriate for go/no-go inspection work in production and quality control environments. The minus designation indicates the gage is sized to the low end of the tolerance band, confirming a hole is at or above minimum acceptable diameter. Machinists, tool and die makers, and quality technicians use this type of gage as a standard part of in-process and final inspection routines.

This plug pin gage is suited for use in job shops, production machining facilities, and inspection departments where hole diameter verification is required. At 0.394 inches, it falls within a common range for drilled, reamed, and bored holes found in general metalworking and light manufacturing. The gage is handled manually and requires no calibration equipment beyond a controlled environment consistent with standard metrology practice.

Key Features

• Class ZZ tolerance class for general-purpose inspection use
• Minus designation targets the low side of the tolerance band for go-type verification
• 0.000200 inch tolerance for precise hole diameter confirmation
• 0.394 inch diameter covers a common drilled and reamed hole size
• Steel construction for durability in shop environments
• Single-piece packaging with a minimum order quantity of one

Compatibility

Designed as an OEM-style replacement or direct-use plug gage for inspection of 0.394 inch nominal diameter holes in general machining and manufacturing quality control applications.

Installation Notes

Plug pin gages are handled by quality technicians and machinists and require no power or tools for use. Store and use the gage in a temperature-stable environment to avoid thermal expansion errors that can affect readings at this tolerance level. Clean the gage and the hole being checked before use to prevent debris from producing false rejections. Do not force the gage into an undersized hole, as this can damage the gage surface and compromise measurement accuracy.