[DURABILITY]- 7 PCS countersink drill bit set for wood made of high carbon steel with EXTRA titanium coating for higher strength and hardness, better heat resistance and wear resistance. This countersink drill bit set is STURDY, DURABLE. Long service life ensured; [COMBO SET OF 7 SIZES WITH ROUND SHANK]- Package includes 7 sizes -3mm, 4mm, 5mm, 6mm,7mm, 8mm, 10mm-metal countersink drill bits to satisfy your various woodworking needs. All countersink drill bits of the set has a straight shank and can fit into all power tools, especially for quick change chuck; Five-edged chamfer design discharges chips from hole on both sides fast and easily; [WIDE APPLICATION]- This 7 sizes countersink wood drill bit set can be widely applied to wooden planks, fiberboard, particle board, plywood, plastic, aluminum board, PVC board and more. Great for wood openings, reaming, chamfering, screw head, and more use; [EASY ASSEMBLY AND DISASSEMBLY]- Package comes with a hex key to easily adjust or disassemble the countersink drill bit and the five-flutes chamfering; [WARM NOTE]- Recommend to use on table mounted drill. Due to the unfixed drilling center of hand drill, bits may break during drilling if they are applied on hand drills. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.