Spi 19-390-4 Class Zz Minus Plug Pin Gage 0.39 in

Product Description

The SPI 19-390-4 is a Class ZZ minus plug pin gage used to verify hole diameters in precision machining and inspection applications. Measuring 0.39 inches in diameter with a tolerance of 0.0002 inches, this gage is designed to check whether a hole is at or within its minimum acceptable size. Machined from steel for durability and dimensional stability, it is a go/no-go style measurement tool used by quality control technicians, machinists, and tool-and-die professionals in manufacturing and fabrication environments.

This pin gage is suited for dimensional inspection on the shop floor or in a quality lab. Class ZZ gages are the standard commercial-grade class for general-purpose hole checking, making this part appropriate for incoming inspection, in-process verification, and final inspection of drilled, reamed, or bored holes in metal, plastic, or composite workpieces. The minus designation indicates the gage is ground below nominal, functioning as a go gage to confirm minimum hole size.

Key Features

• Class ZZ tolerance class for general commercial inspection use
• Minus designation provides go-gage function to verify minimum hole diameter
• 0.0002 inch tolerance for reliable, repeatable measurement
• Steel construction for dimensional stability and long service life
• 0.39 inch nominal diameter for direct substitution in standard gage setups

Compatibility

Designed as a standard Class ZZ minus plug pin gage for use in commercial-grade hole inspection applications requiring a 0.39 inch nominal diameter.

Installation Notes

Pin gages should be handled with clean, dry hands or lint-free gloves to prevent corrosion from skin oils. Store in a protective case away from temperature extremes to maintain calibration integrity. Clean the gage and the workpiece bore before use to ensure accurate readings. Do not force the gage into an undersized hole, as this can damage both the gage and the part.