Below is a list of Copper Suppliers manufacturers from Downers Grove, Illinois. Copper suppliers manufacture and distribute preformed copper and copper alloy billets, blanks and parts. While some applications require pure copper, most products are copper alloys that are mixed with another material, which enhances or improves certain properties. The addition of zinc or tin to copper produces the alloys bronze and brass, which are stronger than unalloyed copper. Lead and tellurium improve chip breaking, while aluminum and silicon alter the metal's strength and malleability properties.