Draper expert 10mm cobalt twist drill draper expert 39091 expert quality a selection of metric sized high speed steel straight shank drills with 5 cobalt the addition of cobalt to hss adds strength and wear resistance for longer life for use with metric helicoil174 thread repair kits display packedmanufactured to din338 and iso2351 specifications draper expert 39091 2mm cobalt twist drill