Spi 30-740-5 Radius Gage 3/8 Inch Convex Concave Leaf

Product Description

The SPI 30-740-5 is a precision radius gage designed to measure and verify both convex and concave radii on machined parts, castings, and fabricated components. Each leaf is ground to a 3/8 inch (0.375 inch) radius and delivers an accuracy of 0.0012 inches, making it suitable for quality control work in machine shops, tool rooms, and fabrication environments. The satin chrome finish on the steel leaf resists corrosion and reduces glare during inspection. Machinists, tool and die makers, and quality technicians use this gage to confirm radius dimensions against a workpiece by fitting the leaf to the surface and checking for light gaps.

This gage is used in industrial and manufacturing settings where consistent radius verification is required. It is appropriate for incoming inspection, in-process quality checks, and final part verification on machined or formed metal components. The single-leaf format covers both convex and concave profiles at the 3/8 inch radius, reducing the need to handle multiple tools for the same nominal size. It fits naturally into a standard radius gage set or works as a standalone replacement leaf.

Key Features

• Measures both convex and concave radii with a single leaf
• 3/8 inch (0.375 inch) radius with 0.0012 inch accuracy
• Satin chrome finish on steel for corrosion resistance and low-glare inspection
• Compact single-leaf format for precise fitment checks on machined surfaces
• Weighs 0.03 pounds for easy handling during inspection tasks

Compatibility

Designed as an OEM-style replacement or supplemental leaf for standard radius gage sets requiring a 3/8 inch convex and concave radius profile.

Installation Notes

No installation is required for this inspection tool. Handle the gage leaf carefully to avoid nicking or scratching the ground radius profile, as surface damage will affect measurement accuracy. Store the leaf in a protective case or pouch when not in use to prevent corrosion and wear. Calibration against a certified reference standard is recommended before use in critical quality applications.