HSS Center Drill centre drill A type B type 1.Material: Hard alloy,HSS6542,9341,4341,4241 2.Surface treatment: bright finish HSS Center Drill ... centre drill A type B type1.Material: Hard alloy,HSS6542,9341,4341 ... can make all kinds of HSS products like end mills,center drill,drill bits and reamers.Wlecome to visit our factory ...