... polished tintanium coating bitstin coating bitshss twist drill bitsThis style is 25PC HSS drill (1-13*0.5)HSS straight shank ... oxide,Black flute & bright shank3.manufactory process:roll forged,edge ground,fully ground4.Standard:DIN 338 (jobber series) DIN 340 ( ... shank twist drills,taper shank drill,SDS drill bits,center drills,step drills,masonry drill,,wood working drill,flat wood bit,Hss reduced ...