Spi 30-738-9 Radius Gage 5/16 Inch Convex Concave

Product Description

The SPI 30-738-9 is a single-leaf radius gage designed to measure both convex and concave radii with a nominal radius of 5/16 inch (0.3125 inch). Finished in satin chrome and constructed from steel, this gage delivers an accuracy of 0.0012 inch, making it suitable for close-tolerance inspection work in fabrication, machining, and HVAC component verification. Machinists, tool-and-die technicians, sheet metal workers, and quality control inspectors use this type of gage to quickly verify fillet and edge radii on formed or machined parts without requiring additional measuring instruments.

This radius gage is suited for bench inspection and in-process quality checks in light manufacturing, metal fabrication shops, and mechanical trade environments. Its compact single-leaf design makes it easy to carry in a technician's apron or tool pouch for spot checks on radius profiles during fitting or assembly. The satin chrome finish reduces glare and resists light corrosion during normal shop use.

Key Features

• Measures both convex and concave radii with a single leaf
• Nominal radius of 5/16 inch (0.3125 inch maximum radius)
• Accuracy of 0.0012 inch for close-tolerance inspection
• Steel construction with satin chrome finish for durability and corrosion resistance
• Compact single-leaf form factor fits easily in a tool pouch or apron pocket

Compatibility

Designed as a general-purpose radius gage for use on machined, formed, or fabricated metal parts requiring verification of a 5/16 inch convex or concave radius profile.

Installation Notes

This is a hand inspection tool and requires no installation. Clean the part surface before gauging to remove chips, burrs, or debris that could affect contact and measurement accuracy. Apply the gage leaf gently against the radius profile and inspect for light gap using a light source if fine accuracy is required. Store the gage in a dry location away from abrasive materials to preserve the finished edges.