Kitchen cabinet
Cabinet doors may feature a variety of materials such as wood, metal or glass. Wood may be solid wood ("breadboard" construction) or engineered wood or may be mixed (e.g. engineered wood panel in a solid wood frame)
Window shutter hardware
Steel - basically a mixture of iron and carbon, although other metals may be added to change the characteristic of the steel (add chrome, get stainless steel; add nickel, get armor plate). The carbon content of steel is closely controlled in its manufacture - the more carbon the "stronger" the steel. Steel varies from iron in that it can be hardened. Heat steel red-hot and quench it and it gets hard, heat iron red hot and quench it and it gets cold.