Spi 19-378-9 Class Zz Minus Plug Pin Gage 0.378 in

Product Description

The SPI 19-378-9 is a Class ZZ minus plug pin gage with a 0.378-inch nominal diameter, designed for go/no-go inspection of bored holes, drilled passages, and machined apertures. Built from steel, it holds a minus tolerance of 0.0002 inches, confirming that a hole meets its minimum acceptable size. Machinists, tool-and-die makers, and quality-control technicians use plug pin gages like this one as a fast, repeatable method for dimensional verification without complex metrology equipment.

This gage is suited for production floor inspection and incoming quality checks in machine shops, manufacturing cells, and fabrication environments. It applies wherever a 0.378-inch diameter hole must be verified to print tolerance. The minus designation means the gage is manufactured undersized relative to nominal, allowing it to function as the go member in a standard gage pair or as a standalone check for minimum hole size acceptance.

Key Features

• Class ZZ accuracy grade for general-purpose inspection use
• Minus tolerance designation confirms minimum hole size acceptance
• 0.0002-inch tolerance for reliable dimensional control
• Steel construction provides durability for repeated shop-floor use
• Compact, single-pin format for quick pass/fail checks

Compatibility

Designed as a standard plug pin gage for dimensional inspection of 0.378-inch diameter holes in machined components across general manufacturing and quality-control applications.

Installation Notes

Plug pin gages are handled by machinists and quality technicians and require no power or special mounting. Store gages in a protected case when not in use to prevent surface damage that would affect accuracy. Clean the hole and gage surface before each check to avoid false readings from debris or cutting fluid. Handle with care to avoid dropping, which can alter the gage geometry or introduce burrs.