Hss twist drill bits High hardress High temperature resistance competive price and good quilty Materials : M35, M42,HSS4241,HSS4341,HSS6542,HSS9341We supply different kinds of drill bits,include standard and un-standard goodsprovied the best customer services.Finish:Black oxide,Bright Finishes,Tin coated,Amber Finished,Rainbowcolor,etcProcess:Forged roll,Polished,Fully groudApplication: For ...