NYLON Sheave/Pulley, Various Types Available, Specially for all kinds of Elevators/lifts ... times of copper. (4) Improved the property of crane, little or non maintenance. (5) Corrosive resistance: non-corrosive benefits for sea ... wheel, locating wheel, worm wheel, chain wheel, synchromesh band wheel, pulley, hopper sheave, walking wheel, maintenance free bearing, etc.