A.3~5mm B.1~2mm C.5~10mm D.10~20mm E.30mm
A.1~2mm B.1~0.2mm C.2~0.3mm D.2~3mm E.越薄越好
A.碳化硅 B.鎢鋼鉆 C.橡皮輪 D.金鋼砂針 E.金鋼石鉆針