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