... hardness, moderate grain force, high roughness, low cardamine.Good wear resistance, long using period. trong temperature, ... non-toxic, no pollution to rice and bran, clean, bright white grain of rice, pure color quality. Series ... oil, and dirty, forbidden to put under sun for long time.Take sands away from the paddy, keep ... under the limitedDon’t make the machine work for a long time, in case effect the ...