ITEM NAME:1/2"+5/8" HSS 6.35mm Hex Shank Chamfer Debur Countersink Drill Bit Set* TEUS.High speed steel countersink for use in steel, iron and more. Category: countersink. Chamfer angle: 82 Degrees. Chamfer angle: 82 degrees. HSS construction for faster cutting and longer life. Material: HSS.