Kangnice 5 Pcs HSS Center 60&deg; Spotting Drill Bits Combined Countersink High Speed Tool General Materials centering hole machining and chamfering machining. Using cobalt high speed steel material Cutting fast, good chip evacuation, edge clear, sharp and durable, the drill shank has a specification lettering (Without protecting chamfers composite center drill) 60 tip angles,Optional Size: 1/8",3/16",1/4",5/16",5/32" Material: HSS,Applicable hardness: HRC40 or less Use: suitable for positioning and Chamfering processing before drilling,Quantity : 1 Set/ 5 Pcs