Spi 19-039-7 Class Zz Minus Plug Pin Gage 0.039 in

Product Description

The SPI 19-039-7 is a Class ZZ minus plug pin gage with a 0.039-inch nominal diameter, manufactured from steel for durability in shop and inspection environments. This go/no-go style pin gage checks hole diameters and bore sizes to a tolerance of 0.0002 inches, making it a reliable tool for quality control and dimensional inspection work. The minus designation means the gage is ground to the lower limit of the tolerance band, which is the standard configuration for plug-type pin gages used to verify minimum hole acceptance. Machinists, toolmakers, and quality technicians use this gage as part of standard incoming and in-process inspection routines.

This pin gage is suited for use in machine shops, manufacturing facilities, and inspection departments where precise hole verification is required. At 0.039 inches in diameter, it falls in the small-diameter range commonly used to check drilled, reamed, or punched holes in precision components. It is appropriate for both production-floor spot checks and more formal metrology workflows where documented gage calibration is required. The compact size and steel construction make it compatible with standard gage handle sets used in light-duty precision measurement applications.

Key Features

• Class ZZ tolerance class suitable for general-purpose inspection and production gaging
• Minus designation ground to the lower limit of the tolerance band for plug-type verification
• 0.0002-inch tolerance ensures repeatable dimensional checks at the 0.039-inch nominal size
• Steel construction provides wear resistance for repeated use in shop environments
• Compact single-pin format compatible with standard pin gage handles

Compatibility

Designed as an OEM-style replacement or supplemental gage pin for standard pin gage handle sets used with small-diameter Class ZZ plug gages in general machining and inspection applications.

Installation Notes

Pin gages should be inserted into gage handles by qualified machinists or quality technicians following the handle manufacturer's seating and locking instructions. Clean the gage pin and the bore being checked before use to avoid measurement error from debris or burrs. Do not force the pin into an undersized hole, as this can damage the gage or alter its calibration. Gage pins should be recalibrated periodically per your facility's gage control program to maintain measurement traceability.