High Quality MaterialThese drill bits are made of HSS4241, anti-rust and durable, the cutting edge of the drill bit is smooth, without chatter or fluted edges. For clean and precise milling, chamfering or beveling of round holes in workpieces. Internal chip evacuationThe countersunk bit eliminates chips when cutting, reduces clogging and prevents metal splashing, making cutting faster, cleaner and quieter, and the round handle can be used with a variety of systems. Superior EfficiencyHSS coated chamfering tool has high precision and sharpness, the tip is at 90 angle for clean and precise countersinking. Increase productivity and save time and energy in domestic and industrial operations. WIDE APPLICATIONSuitable for cutting plywood, wood, acrylic, PVC board, plastic and metal. When working with materials, the drill bit must be kept cool between drill holes. (Note: It is necessary to cooperate with the bench drill operation, and the electric hand drill cannot be used.) Package IncludedOur set contains 4 HSS countersink drill bits for deburring, metalworking and non-metallic cutting. 2-5mm, 5-10mm, 10-15mm, 15-20mm are available in four different sizes to meet your different cutting needs.