HEAVY DUTY GEAR BOX speed ratio 1:1 or 2 ... or aluminum gearbox are available. NOSEN HEAVY DUTY GEAR BOX RNV-Series,cubic shape of gearbox.Model: RNV-065,RNV-090 ... 1.Spiral bevel gears: alloy steel,case hardened,be of high rigidity and wear risistance2.Bearings: taper roller bearings, ... bear larger torque3.Gearbox: cast iron, six faces of gearbox are machined by milling machine,gloss surfaces4.Input& ...