* The handle is made of high quality carbon steelmaterial,strong hardness and very durable. * High quality alloy blade,make blade more sharp and durable,it's head adopt arc curve design,beneficial to chip removal, perforation is more efficient. * Sharp edge,high hardness,accurate positioning,high precision,smooth cutting,impact resistance,high toughness.Trepanning more smooth,less noise. * Enable woodworkers to drill holes without passing through the material when a clean and precise bottom to a hole. * Used for wood perforation,spherical door tip installation,drawer tip,plastic products,wood,plywood,etc.. * Suitable for hand held electric drill,stand motor-driven drilling machine and mobile ribbon type magnetism drilling machine.