Made of classic carbon steel, high hardness, the blade is sharp, durable and has a long service life. Use the hex wrench to adjust the depth of the countertop sleeve and the drilling depth for screws of different lengths. Complete specifications can satisfy everything you demandSuitable for bench drill, hand drill and conventional electric drill. Perfect for wood, fiberboard, particle board, plywood, plastic, PVC, rubber, Precise punching can be done quickly and accurately. The external thread can help discharge waste when drilling, ensuring successful drillingPackage Contents: 5 woodworking drill bits, very suitable for use with wood holes of multiple sizesCone drill bits for woodworking. Features:Sizes: 2.8mm, 3mm, 3.2mm, 3.5mm, 4mm.Weight: 31 grams for a single piece, 155 grams for a set of 5 pieces.Material: YG8 alloy, cutting body 45# carbon steel, surface sprayed.Features of round handle drill bit:1. Hard alloy cutter head, sharp blade, wear-resistant and durable, the blade does not fall, high stability2. Quality counter bore attaches to flats on shank with 2 hex screws for a secure fit and can be adjusted for controlled pilot hole depth3. Universal round shank, widely used for DIY, home and general construction or engineering, etc. Package Content: 5 Countersunk Drill Bits.