UHMW stands for Ultra-high-molecular-weight polyethylene, which is a subset of the thermoplastic polyethylene. It is also known as high-modulus polyethylene or HMPE. UHMW has extremely long chains, with a molecular mass usually between 3.5 and 7.5 million amu. It is made up of extremely long chains of polyethylene, which all align in the same direction. UHMW derives its strength largely from the length of each individual molecule (chain). Van der Waals forces between the molecules are relatively weak for each atom of overlap between the molecules, but because the molecules are very long, large overlaps can exist, adding up to the ability to carry larger shear forces from molecule to molecule.

UHMW is an extremely tough plastic with high abrasion and wear resistance. It is used for a wide range of wear applications. UHMW is suitable for a wide range of temperatures and fares well outdoors. It is used in the manufacture of PVC windows and doors, as it can endure the heat required to soften the PVC-based materials. UHMW is also used in the manufacture of conveyor systems, packaging machinery components, and gears. It is employed to design mechanical parts, guides, wear strips, anti-friction liners, and chutes, among others. UHMW is also used in the natural resources sectors to optimize the transportation of bulk materials. UHMW is FDA compliant and is therefore popular with the food industry. It is used in the manufacture of rollers, chain guides, conveyor parts, and chute liners. UHMW is also used in body armor and prostheses due to its biocompatibility, strength, and wear resistance.