Teeth with carbide tungsten grit is used for drilling smooth through holes in the floor and wall tiles, cellular concrete, brick, slate, etc.. Used with screwdrivers, drills and light punches in the unstressed mode for drilling holes for sockets, switches, pipes and communication. Features carbide tungsten alloy is resistant to heavy loads and has a long service life. You get a smooth hole through the drill guide. Quickly and reliably fixed to the carrier through the lateral grooves. Core bit (cutter) is made from high quality tool steel and steadily transfers exercise. The cutting portion is uniformly coated with tungsten carbide grit which provides a comfortable drilling without chipping or cracking. Pilot drill does not give the crown to go away and allows you to make smooth holes. hole depth 64 mm. Make at least one opening of the crown, and you will feel how fast it does the job. To crown fits SD0399 and SD0398 holder. Holder is not supplied with a crown.