FIELD: cutting metal and electric current conductive materials, possibly investigation of tool strength and working articles in machine tools with different autoimmunization degree with use of drills having changeable polyhedral tips. SUBSTANCE: drill includes body with chip grooves and openings for supplying cutting fluid, two arranged asymmetrically relative to axis of housing changeable polyhedral cutting tips mounted in basing seats and screws for securing them. In order to control condition of cutting edges at drilling process, drill is provided with dielectric elastic sleeves and screw that is mounted with possibility of connecting to electric circuit of drilled part on end of body behind peripheral cutting tip in parallel relative to axis of body. Outer point of screw head is radially shifted relative to peripheral changeable cutting tip forming cylindrical surface of drilled opening by value equal to admissible wear value of drill. EFFECT: enhanced strength of drill cutting edges due to controlling their wear at drilling process. 3 dwg
