When purchasing aluminum outdoor patio furniture, you must understand the differences between wrought aluminum patio furniture and cast aluminum patio furniture. Most aluminum patio furniture is of the wrought variety, so if a set simply says it is made of aluminum, it is safe to say that it is wrought aluminum. Cast aluminum, however, is melted and poured into a cast to shape it how the designer wants it to be shaped. Cast aluminum patio furniture typically features more intricate details, and each item from a line will be identical.