Roller main categories: Parallel roller common type roller, comb-type roller, forward-Roller, steel, rubber type roller, screw-type roller and the like. Spherical roller with universal type, friction reversible roller, strong type roller, tapered roller, screw-type roller, combination roller and the like. Buffer roller spring plate roller, roller cushion ring type, strong buffer type roller, roller adjustable elastic type, hanging type roller and the like. Radial positioning roller assembly usually cylindrical roller tube positioning belt conveyor idlers price, high roller tube is to produce high quality a prerequisite for high-roller belt conveyor roller, since the roller tube the outer diameter is usually not working, that roundness roller tube is unchanged, although it has an error, the outer diameter of the roller tube should be the reference roller assembly. This allows the original inherent cylindrical roller tube close to beating the cylindrical roller finished beating.