... 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 ... finish 3.Size: A type 0.5-6.0 B type 1.0-6.34.Technicial:fully groundCenter drill ... sprial flute etc.We can make all kinds of HSS products like end mills,center drill,drill bits ...