... 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,HSS6542,9341,4341,4241 ... 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