... 3)Corrosive resistance 1. Special properties:Rare earth and nanometer strengthened engineering plastic is a kind of ... boom, this provides mobile cranes with greater stability and lifting capability.(2) Improved wire rope life: self ... sheave, roller, gear, shaft sleeves, supporting wheel, locating wheel,worm wheel, chain wheel, synchromesh band wheel, pulley, hopper sheave, walkingwheel, maintenance free ...