Engineering plastics are a group of plastic materials that have better mechanical and/or thermal properties than the more widely used commodity plastics (such as polystyrene, PVC, polypropylene and polyethylene).
Being more expensive, engineering plastics are produced in lower quantities and tend to be used for smaller objects or low-volume applications (such as mechanical parts), rather than for bulk and high-volume ends (like containers and packaging).
The term usually refers to thermoplastic materials rather than thermosetting ones. Examples of engineering plastics include acrylonitrile butadiene styrene (ABS), used for car bumpers, dashboard trim; polycarbonates, used in motorcycle helmets; and polyamides (nylons), used for skis and ski boots.
Engineering plastics have gradually replaced traditional engineering materials such as wood or metal in many applications. Besides equalling or surpassing them in weight/strength and other properties, engineering plastics are much easier to manufacture, especially in complicated shapes.