A high-speed machining tool made of a steel-bonded carbide and a method for preparing the same relate to the technical field of lathe tools made of steel-bonded carbides, and overcome the problems of traditional steel-bonded carbide lathe tools about low hardness and low toughness. The high-speed machining tool includes a skeleton, a main body, and a coating. The main body is consolidated by the skeleton from inside. The skeleton and the main body are both ringlike in shape. The main body has its outer surface covered by the coating. The high-speed machining tool is such made that the skeleton is hard and the main body is tough. The blade of the tool is hard and can transfer vibrations to the main body, thereby protecting the tool from brittle fractures and improving the overall performance of the tool.

A step drill bit includes a body with a plurality of cylindrical steps of increasing diameter from a front end toward a rear end, a flute extending from the front end toward the rear end, and cutting edges at junctions between each step and the flute. A cutting insert with a hardness greater than the hardness of the body is coupled to the front end portion and at least partially defines a cutting head portion. The cutting head portion includes a center cutting tip, a cutting edge extending radially outward from the cutting tip, a rake face extending from the cutting edge toward the rear end portion, a relief face extending from the cutting edge in a circumferential direction opposite a rotational cutting direction of the drill bit, and a chip clearing recess in communication with the flute, with the rake face facing the chip clearing recess.

A long twist drill includes a shank and a drill body having a drill tip (16). The twist drill has a length L and an outer diameter D, and has a cemented carbide or high speed steel substrate and a coating of at least one layer. The quota L/D is at least 16. The twist drill has two cutting segments at the tip and two flutes chip. The twist drill is provided with holes for fluid opening in the tip. The twist drill has an axial web thinning angle GAA, which is 40 to 50°. The twist drill further has a web that back tapers such that a web diameter gets smaller in a direction away from the tip towards the shank within an axial distance.

A coated cutting tool comprising a substrate and a coating layer provided on a surface of the substrate, wherein: the coating layer comprises at least one -type aluminum oxide layer; and a texture coefficient TC (0,0,12) of a (0,0,12) plane of the -type aluminum oxide layer is from 4.0 or more to 8.4 or less; and a texture coefficient TC (1,0,10) of a (1,0,10) plane thereof is from 0.4 or more to 3.0 or less.

A high-speed machining tool made of a steel-bonded carbide and a method for preparing the same relate to the technical field of lathe tools made of steel-bonded carbides, and overcome the problems of traditional steel-bonded carbide lathe tools about low hardness and low toughness. The high-speed machining tool includes a skeleton, a main body, and a coating. The main body is consolidated by the skeleton from inside. The skeleton and the main body are both ringlike in shape. The main body has its outer surface covered by the coating. The high-speed machining tool is such made that the skeleton is hard and the main body is tough. The blade of the tool is hard and can transfer vibrations to the main body, thereby protecting the tool from brittle fractures and improving the overall performance of the tool.

A coated cutting tool comprising a substrate and a coating layer provided on a surface of the substrate, wherein: the coating layer comprises at least one -type aluminum oxide layer; and a texture coefficient TC (0,0,12) of a (0,0,12) plane of the -type aluminum oxide layer is from 4.0 or more to 8.4 or less; and a texture coefficient TC (1,0,10) of a (1,0,10) plane thereof is from 0.4 or more to 3.0 or less.

A coated cutting tool and a hard and wear resistant coating for a body include at least one metal based nitride layer. The layer is (ZrxCrl-x-y-zAlyMez)Na with 0.55<x<0.85, 0.05<y<0.45, 0z<0.20, 0.95<a<1.10, and Me is one or more of the elements: Y, Ti, V, Nb, Ta, Mo, W, Mn or Si. The layer can have a thickness between 0.5 m and 15 m and be comprisied of a single cubic phase or a single hexagonal phase or a mixture thereof. In an exemplary embodiment, the layer is a cubic phase of a sodium chloride structure. The layer can be deposited using cathodic arc evaporation and is useful for metal cutting applications generating high temperatures.