1.made with 9CrSi,D2,HSS, M2, 440b, 440c, etc 2.tolerance within 0.002mm 3.OEM for customer 4.more ... hardness even, precision processing manufacturing. Especially for all kinds of cold and hot rolling steel plate, XiGangPian and galvanized iron ... its processing precision, more demanding, for plane, our factory is made of super precision grinding machine plane, with special grinding method, grinding ...