Spi 31-442-7 Small Hole Gage 0.2 to 0.3 Inch

Product Description

The SPI 31-442-7 is a small hole gage used to measure the internal diameter of bores, holes, and slots with precision. It covers a measurement range of 0.2 to 0.3 inches and reaches a gage depth of 1-3/16 inches, making it well-suited for shallow to moderate-depth bores. The full ball contact style provides consistent, repeatable contact with the bore wall. Finished in satin chrome, the tool resists corrosion and reduces glare during use. At 3 inches overall length, it is compact enough for confined work areas. Machinists, tool-and-die workers, and maintenance technicians use this gage when checking tight-tolerance internal features that dial bore gages cannot access.

This gage is used in precision measurement applications across machining, manufacturing, and mechanical maintenance. It is suited for inspecting small bores in hydraulic components, valve bodies, pump housings, and other assemblies where accurate internal diameter verification is required. The 0.2 to 0.3 inch range targets small-diameter features that are common in fine-pitch mechanical work. The tool is used in conjunction with a micrometer to transfer and read the measurement.

Key Features

• Measurement range of 0.2 to 0.3 inches covers small internal bore diameters
• Full ball contact style delivers consistent wall contact and repeatable results
• 1-3/16 inch gage depth allows reach into moderate-depth bores
• 3 inch overall length keeps the tool compact for use in tight spaces
• Satin chrome finish resists corrosion and reduces surface glare

Compatibility

Designed as a general-purpose small hole gage for use with any outside micrometer capable of reading in the 0.2 to 0.3 inch range. No proprietary system compatibility required.

Installation Notes

This is a hand measurement tool and requires no installation. Insert the ball end into the bore, expand the contact to a light drag fit, then lock and withdraw the gage for measurement with a micrometer. Handle the satin chrome finish with care to avoid corrosion from prolonged skin contact — wipe clean with a lightly oiled cloth after use. Store in a protective case away from other tools to prevent contact damage to the ball tip.