The invention relates to a method for producing a roughing tool (1), particularly a circular milling tool, comprising the following steps: fitting a lateral surface of a tool base body (10) that can be rotatably driven about an axis of rotation (2) with a number of cutting element blanks (20′) that are staggered in the axial and/or peripheral direction, such that a free edge of each cutting element blank (20′) protrudes out of the lateral surface in the mounted state; inserting a microtoothing comprising a plurality of axially spaced cutting teeth (21) into the respective free edges of the cutting element blanks (20′) by a material removal method, preferably by thermal machining, particularly preferably by eroding, in the premounted state on the tool base body (10). The invention further relates to a roughing tool produced by means of such a method.

A multi-flute ball end mill of the present invention includes: a shank portion configured to rotate about a rotational axis; a cutting edge portion; three or more ball edges formed on the cutting edge portion; gashes formed between the ball edges; peripheral cutting edges continuous with end portions of the ball edges on the shank portion side; and flutes formed between the peripheral cutting edges continuously with the gashes. The degree of curvature of the ball edges is 35% to 55%. Each of the gashes includes four faces of a rake face of each of the ball edges, a gash wall face, a first gash face, and a second gash face. The second gash face is formed such that the closer the second gash face is to the rotation center point, the more inwardly the second gash face enters a second face of each of the ball edges.

A formed rotary cutting tool includes a cutting edge defining a cutting edge diameter that is increased and reduced in a direction of an axis of the tool, so as to have at least one neck portion in which the cutting edge diameter is minimized. The cutting tool includes a roughing portion which is provided on a periphery thereof and which is constituted by a succession of protrusions and recesses arranged in the direction of the axis. The roughing portion includes (i) a fine roughing portion that is provided in at least one of the at least one neck portion, and (ii) another portion that is provided in a portion that is other than the at least one of the at least one neck portion. The fine roughing portion of the roughing portion is different in characteristics from the above-described another portion of the roughing portion.

A rotary tool of the present aspect has a body and a cutting edge positioned on the outer periphery of the body. The cutting edge has a first section and a second section when viewed on an imaginary plane defined by cutting a rotational trajectory of the rotary tool on a plane including a rotational axis. The first section has a first region and a second region. A first radius of curvature of the first region is greater than a second radius of curvature of the second region in at least one of a plurality of the first sections.

A rotary tool of the present aspect has a body and a cutting edge positioned on the outer periphery of the body. The cutting edge has a first section and a second section when viewed on an imaginary plane defined by cutting a rotational trajectory of the rotary tool on a plane including a rotational axis. The first section has a first region and a second region. A first radius of curvature of the first region is greater than a second radius of curvature of the second region in at least one of a plurality of the first sections.

A copper-alloy heat-dissipation structure with a milled surface includes a heat-dissipation main body. The heat-dissipation main body has a first milled surface and a second milled surface that are opposite to each other, where heat-dissipation fins are formed on the first milled surface, and the maximum height roughness Rz of the second milled surface ranges from 1.5 μm to 5.4 μm.

A roughening tool for roughening the cylindrical surface of a bore in a particular metallic workpiece, e.g. the piston running surface of a cylinder bore or cylinder liner in an internal combustion engine, by generating a defined microstructure of a plurality of circumferentially spaced apart circumferential microgrooves. The roughening tool has a tool main body which can be driven in rotation about an axis of rotation and a multiplicity of circumferentially cutting cutting tools arranged at a defined axial distance from one another on the tool main body. According to the invention, the cutting tools are each formed from a disc milling cutter and each disc milling cutter has at least one cutting element with a multiplicity of cutting teeth arranged at an axial distance from one another. In addition, a method for roughening a cylindrical surface.

The rotary cutting tool of the invention has helicoidal peripheral cutting edges with a wavy profile.

The invention relates to a method for producing a roughing tool (1), particularly a circular milling tool, comprising the following steps: fitting a lateral surface of a tool base body (10) that can be rotatably driven about an axis of rotation (2) with a number of cutting element blanks (20) that are staggered in the axial and/or peripheral direction, such that a free edge of each cutting element blank (20) protrudes out of the lateral surface in the mounted state; inserting a microtoothing comprising a plurality of axially spaced cutting teeth (21) into the respective free edges of the cutting element blanks (20) by a material removal method, preferably by thermal machining, particularly preferably by eroding, in the premounted state on the tool base body (10). The invention further relates to a roughing tool produced by means of such a method.

The invention relates to an apparatus for processing cylinder walls of internal combustion engines (1), including a cutting element (4). The cutting element (4) is arranged on a rotary cutting ring (3). The cutting element (4) has a slit contour (5) with a plurality of cutting edges (6) arranged next to each other in a direction of an axis of rotation of the rotary cutting ring. And, the individual cutting edges (6) face in a direction of rotation of the rotary cutting ring.