Injection molding is a manufacturing process for producing parts from both thermoplastic and thermosetting plastic materials. Molten plastic is injected at high pressure into a mold, which is the inverse of the product's shape.

 

After a product is designed, usually by an industrial designer or an engineer, molds are made by a mold maker (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.

 

Injection molding is the most common method of production, with some commonly made items including bottle caps and outdoor furniture. Injection molding typically is capable of tolerances equivalent to an IT Grade of about 9-14.