.4,2B,BA,HL,8K,Mirror finish and so on.?2B:The?surface?brightness?and?flatness?of?2B?is?better?than?2D.?Then?through?a?special?surface?treatment?to?improve?its?mechanical?properties,No2B?could?nearly?satisfy?comprehensive?uses.?No.1:Polished?with?abrasive?belt?of?grit#100-#200,?have?better?brightness?with?discontinuous?coarse?stria,?used?as?inner?and?external?ornaments?for?building,?electrical?appliances?and?kitchen?utensils?etc.?No.4 :olish