The process used for producing parts from both thermoplastic and thermosetting plastic materials. Material is inserted into a heated barrel, mixed, and forced into a mold cavity where it cools and hardens to the configuration of the mold. After being engineered, molds are made by a moldmaker (or toolmaker) from metal, usually either steel or aluminum, and precision-machined to form the features of the desired part. Injection molding is widely used for manufacturing a variety of parts, from the smallest component to entire body panels of cars.