Starrett 50639 Radius Gage 5/16 Inch Stainless Steel

Product Description

The STARRETT 50639 is a single-leaf radius gage designed to verify both convex and concave radii on machined parts, castings, and fabricated components. Built from stainless steel with a satin chrome finish, it measures a fixed radius of 5/16 inch (0.31 inches maximum radius). Each leaf is double-ended, providing one convex profile and one concave profile for checking inside and outside radii with a single tool. Machinists, tool-and-die workers, and quality control technicians use radius gages to confirm fillet and corner radii against print specifications during inspection or in-process fitting. The part weighs 0.05 pounds.

This radius gage is suited for use in machine shops, fabrication environments, and maintenance facilities where dimensional verification of curved surfaces is required. It is typically used alongside surface plates, vises, or directly on the workpiece to confirm that a machined or ground radius matches the design specification. The single-leaf format is practical when only one specific radius size is needed on the job, reducing clutter in a toolbox or gage kit.

Key Features

• Measures a fixed radius of 5/16 inch (0.31 inches) for consistent, repeatable inspection
• Double-ended leaf provides both convex and concave radius profiles per gage
• Stainless steel construction resists corrosion and wear in shop environments
• Satin chrome finish reduces glare during visual fit checks
• Lightweight at 0.05 pounds, easy to carry in a tool pouch or gage roll

Compatibility

Designed as a standard single-leaf radius gage for general dimensional inspection of convex and concave radii on machined, cast, or fabricated workpieces where a 5/16 inch radius specification applies.

Installation Notes

Radius gages are inspection tools and do not require permanent installation. Clean the contact surface of the gage and the workpiece before use to ensure accurate fit. Hold the gage leaf firmly against the radius being checked and view the fit against a light source to identify gaps. Store the gage in a protective case or roll when not in use to prevent damage to the profiled edges.