Abstract: A stair tread and method of manufacturing same is disclosed. The stair tread comprises a rigid frame which is encapsulated with a structural plastic material. In the preferred embodiment, the rigid frame is made from steel and the encapsulating structural plastic is a polyol and isocyanate blend which is applied to the rigid frame by the reaction injection molding process. The stair tread exhibits the advantages of a bar grating stair tread and the corrosions resistance of a plastic stair tread while being low cost and efficient to manufacture.