6PCS 1/4" Hex 5 Flute 90 Degree Countersink Drill Bits: Made of high speed steel and with 6 different diameter sizes 6mm(1/4"), 8mm(5/16"), 9mm(3/8"), 12mm(1/2"), 16mm(5/8"), 19mm(3/4"), All have 90° angle on the tip for clean and precise countersinking. The cutting edge is hardened and honed for sharpness. -Free, five flutes designed with staggered cutting teeth arranged to ensure free chip flow and fast cutting without chattering. 7Pcs Triple Point Countersink Drill Bits for Woodworking: Made of high speed steel with good abrasion resistance and durable, includes 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 10mm for hole drilling pilots, the large flute chip removal drill bit and five edge chamfers allow faster and easier discharge of sawdust. Coated with titanium, the chamfer cutter kit is rust-resistant and has a long service life. 8PCS 3/8" Shank Wood Plug Cutter Drill Bit: Made of durable carbon steel, used for 1/4", 3/8", 1/2", 5/8" tapered wood plugs to cover recessed screw holes or hide