Different parts scrounged from printers, VHS cassette hubs, window catches, innards from dishwashers, snap locks for belts, helmets etc. Used for form/ temp/ humidity stable bearings, gears, gliding or other parts under wear. Brand names: Delrin, Ultraform & Hostaform. Lowest friction coeff around - can be oiled/ greased to even less friction. Easily machined: decent speed, firm feed, cool cutting edge w compressed air.