【MATERIAL - CARBIDE】: Made of cemented carbide and heat treated. High hardness and heat resistance, the high temperature generated during drilling does not deform it, also wear-resistant, can be used for a very long time. High concentricity, so the machining precision is high and the noise is low. 【LARGE VERSION - 42 MM】: The package contains 42 mm. Guided by the circular edge, the holes all have an arc in each direction; ensures a true, precise and clean drill hole with a flat bottom and quick removal of waste, ensuring efficient work. 【X-wing design for precision】: The head ensures visibility and stability during operation. The central spur of each drill bit ensures precise drilling and prevents walking and wobbling during operation, creating perfectly round and precise holes with the central spur design, vertical drilling machine, electric hand drill, motorized pillar drill and movable magnetic tape drill for mounting a spherical door spike, drawer; Perforation on wood products,