Spi 19-355-7 Class Zz Minus Plug Pin Gage 0.355 in

Product Description

The SPI 19-355-7 is a Class ZZ minus plug pin gage machined from steel, used to verify that a hole or bore meets a minimum dimensional tolerance threshold. At 0.355 inches in diameter, this pin gage is manufactured to a minus tolerance of 0.0002 inches, meaning the actual pin diameter is held below the nominal dimension within that allowable deviation. Plug pin gages are go/no-go measurement tools used in precision inspection work across machining, fabrication, and quality control environments. Licensed machinists, toolmakers, and quality technicians are the primary users of this type of gage.

This gage is suited for inspection of drilled, reamed, or bored holes in metal, plastic, or composite workpieces where tight dimensional control is required. Class ZZ is the commercial-grade tolerance class for plug gages, appropriate for general inspection applications where extreme gage accuracy is not required. The minus designation means the gage is used to check that a hole is at or above the minimum allowable diameter, making it the go gage in a standard go/no-go pair. It is commonly used on production floors and in job shops handling close-tolerance work.

Key Features

• Class ZZ minus tolerance class for commercial-grade go-gage inspection
• 0.355-inch nominal diameter with 0.0002-inch minus tolerance
• Steel construction for durability in production inspection environments
• Compact, lightweight design at 0.2 pounds for easy single-hand use
• Single-piece packaging suitable for individual replacement or kit supplementation

Compatibility

Designed as a go-style pin gage for use in standard plug gage handles and holders sized for 0.355-inch diameter pins, consistent with common commercial pin gage set systems.

Installation Notes

Pin gages should be handled with clean, dry gloves or a gage cloth to prevent corrosion from skin oils. Insert the pin into the bore with light, even hand pressure only — do not force the pin or use tools to drive it. Store the gage in a protective case away from temperature extremes to maintain calibration integrity. Periodic recalibration against a certified master reference is recommended per applicable quality system requirements.