Spi 19-138-7 Class Zz Minus Plug Pin Gage 0.138 in

Product Description

The SPI 19-138-7 is a Class ZZ minus plug pin gage used to verify hole diameters to a nominal size of 0.138 inches. Built from steel, it delivers a tolerance of 0.0002 inches, making it suitable for go/no-go inspection work on production floors and in quality control environments. A minus gage is ground below nominal, confirming that a hole has not been cut undersize. Machinists, toolmakers, and quality technicians use plug pin gages as part of standard dimensional inspection routines when checking drilled, reamed, or punched holes.

This gage is appropriate for use in manufacturing, fabrication, and inspection settings where small-diameter hole verification is required. At 0.138 inches nominal diameter, it covers a common drill size range used in light metalworking and precision assembly. It is well suited for bench inspection, incoming material checks, and in-process quality verification on machined components.

Key Features

• Class ZZ tolerance class for general-purpose inspection work
• Minus designation confirms the gage is ground below nominal size
• 0.0002-inch tolerance for precise hole-size verification
• Steel construction for durability in shop environments
• 0.138-inch nominal diameter covers a common small-bore drill size

Compatibility

Designed as a standard Class ZZ minus plug pin gage for general-purpose dimensional inspection of 0.138-inch nominal diameter holes in metalworking and manufacturing applications.

Installation Notes

Plug pin gages are handled and used by machinists and quality inspection personnel, not installed in the conventional sense. Clean the gage and the hole being inspected before use to prevent debris from affecting readings. Store the gage in its case or a protected location to avoid surface damage that could affect accuracy. Periodic calibration against a traceable standard is recommended to confirm the gage remains within tolerance.