Copper 10w3 Round Bar made of a copper-tungsten alloy containing approximately 75% tungsten and 25% copper. This composition gives the alloy excellent wear and arc erosion resistance from the tungsten along with good electrical and thermal conductivity from the copper. Copper 10w3 round bars are commonly used for applications like electrical discharge machining (EDM) electrodes, welding electrodes (e.g. projection and seam welding), and tooling that requires combined wear resistance and conductivity.