Stainless Steel Material: The radius wedge gauge is made of stainless steel, this radius wedge gauge is durable and rust-proof. Clearly marked: Each radius wedge gauge is clearly marked so you can identify the blade you need. Very Useful Tool Gauge & Die Makers: Metric kits are ideal for tool and die makers, machinists, screwdrivers, model makers, machinists and other machinists to design and check the radius of tools, dies, templates and more. Meet Different Needs: There are four different shapes and sizes of radium rice to meet different needs. The radius gauge checks the curvature radius of the bump on the surface of the workpiece, and can also be used as a limit gauge, a common tool. Features: This radius gauge has two types of inserts for checking convex and concave surfaces. The special shape of the insert can be used to measure angles or shoulder fillets and radii.