ITEM NAME:3pcs 12-19mm 5 Flutes HSS 1/4 Inch Round Shank Countersink Drills Power Tool Z.Five Flute Chamfer Debur Countersink 1/4" Hex. Item Type: Countersink. size:12mm 16mm 19mm. Shank Size: 1/4 6.3mm Round Shank. 1/4" Round Shank. 90 Degree chamfer. Application Material:Wood,plastic,Aluminum plate etc.