This scale is based on the relative abrasiveness of minerals . 此硬度计的依据是矿物的相对研磨能力。
2.
Dressing is definitely a treatment of a wheel face to restore or change its cutting action and any truing or sharpening of the face is purely coincidental 将砂轮平滑表面,包围在磨料附近的结合剂去除,使磨料锐角能适当地露出砂轮表面,以产生研磨能力之作业称之。