About this item Countersink drill bit set is include 5 pcs of drill bits in 5 different sizes to satisfy you all demand. The most often used sizes for carpenters, cabinet, furniture makers and other wood working trades. Standard 1/4 inch hex shank is quick change compatible and has an adjustable counter sleeve depth with Allen wrench. Countersink drill bit erfect for wooden planks, plastic, soft metals, fiber board, particle board, plywood, alumiumn board etc. Countersink drill bit is made by high speed steel, this countersink drill bit is easy to use. Meanwhile compared with ordinary the drill accuracy more high. The countersink drill bit have self-starting point and five-fluted design eliminates chatter and vibration for smooth operation to make clean, accurate and burr-free cuts.