A method for drilling through an assembly forming a stack of at least two different materials uses a drill bit having at least a first cutting edge and a second cutting edge inclined in an axial plane of the drill bit so that the end of the drill bit has a projecting conical shape. The first cutting edge is configured to drill a first material. The second cutting edge is made differently from the first cutting edge, to drill a second material. A first rotational drive axis of the drill bit is laterally offset during the drilling by an offset distance D relative to the axis of the drill bit in a direction opposite the first cutting edge when the drill bit is drilling through the first material, and alternately, in a direction opposite the second cutting edge when the drill bit is drilling through the second material.

A holesaw assembly includes a holesaw and a pilot bit. The holesaw includes a hollow cup defining a center axis. The cup has a round base perpendicular to the center axis and a peripheral wall coupled to and extending axially forward of the base to a peripheral edge at a free end of the wall. The pilot bit is received in the holesaw along the center axis. The pilot bit has a shaft received in the base, a cutting head coupled to a front end of the shaft, and an at least partially threaded tip coupled to a front end of the cutting head. The holesaw is free of any radial cutting elements disposed inside the cup between the drill bit and the peripheral wall of the cup.

A laser beam is transmitted through a drill bit comprising diamond or other suitable light-transmitting material having sufficient hardness. The laser beam exits a tip of the drill bit, thereby heating and softening the material being drilled at and/or near the interface of the drill with the material being drilled. The process may be utilized to drill hard and brittle materials such as ceramics and semiconductors, composites and ceramic matrix composites. The process may cause high pressure phase transformation, resulting in a more ductile and plastic material near the drill point/tip. The process provides more rapid drilling, improved surface quality in drilled holes, and less tool wear.

A drilling tool is configured to perform drilling and/or percussive work on materials such as stone, concrete and/or reinforced concrete. The drilling tool has a fastening region and a working region. The working region has a working body and at least one cutting element projecting axially and/or radially in relation to the working body. The at least one cutting element has at least one first cutting edge and at least one second cutting edge. The at least one second cutting edge is configured to serve as a replacement cutting edge and/or as an auxiliary cutting edge, and the at least one second cutting edge is set back, at least partly, in relation to the at least one first cutting edge of the drilling tool, axially along a longitudinal axis of the drilling tool, in a direction towards the fastening region.

The present disclosure relates to cutting tools and cutting inserts in general, and more particularly to the specific shapes of cutting edges on cutting tools and cutting inserts. In an embodiment, a cutting tool with a cutting edge formed as a sinusoidal curve is provided. In an embodiment, a rotary drill bit including a cutting insert comprising a sinusoidal curve is provided.

A rotary tool, in particular drilling tool, extends along a longitudinal axis and has an end surface; a brad point; and at least one major cutting edge extending outward up to an edge corner. A first free surface segment adjoins the major cutting edge, and a second free surface segment in turn adjoins said first free surface segment. To keep the stress, in particular the wear, low in the region of the end surface, the first free surface segment has a lower average abrasiveness than the second free surface segment.

A cutting element for use in a cutting operation, comprising a cutting edge (CE) capable of cutting out material from a workpiece during the operation, to form therein a workpiece corner of angle alpha. There exists at least one view of the cutting edge in which a portion of the cutting edge is delimitable by a first (L1) and a second (L2) line oriented tangentially to the portion of the cutting edge portion at respective tangency points A and B. The lines form therebetween a cutting angle corresponding to the workpiece corner angle alpha and have a vertex 0. For a bisector of the cutting angle intersecting the portion of the cutting edge at the point C, the projection C of the point C of the portion of the cutting edge on a line OL passing through the vertex 0 perpendicularly to the plane of the one view is located between projections A1 and B of the respective points A and B of the portion of the cutting edge on the line OL.

A drill structure includes a shank part and a flute part. A chisel edge is formed on the front end of the flute part and two primary relief faces with tile directions toward the shank part are symmetrically formed on the two sides of the chisel edge. Each primary relief face has a cutting edge, a knife-back edge, and an outer edge. The outer edges are respectively helically extended around the periphery of the flute part to form two helical cutting edges and two helical grooves. Two assist relief faces are respectively formed on the inner walls of the two helical grooves, and every assist relief face is connected with the cutting edge of one primary relief face and portion of the knife-back edge of another primary relief face. The drill structure can decrease the thickness of the chisel edge, reduces the resistance during drilling, and increases the life.

A drill including: a drill main body that rotates about an axis of the drill main body; a chip discharge groove formed on an outer periphery of a tip portion of the drill main body; and a cutting edge formed on the tip portion of the drill main body, a rake face of the cutting edge being a wall surface of the chip discharge groove facing a rotation direction of the drill is provided. The cutting edge includes: a major cutting edge portion provided on an inner peripheral side of the tip portion of the drill main body; a chamfer portion provided on a posterior outer-peripheral side relative to the major cutting edge portion; and a convex curved portion that is provided between the major cutting edge portion and the chamfer portion, the convex curved portion being directed toward a posterior end side of the drill main body from the inner peripheral side to the outer peripheral side with a convex curved shape viewed from a side facing the rake face.

According to one implementation, a drill that drills at least one of a composite material and a metal is provided. A web thickness at least at a tip of the drill is not less than 5% and less than 25% of at least one diameter of the drill. Further, according to one implementation, a method of manufacturing a drilled product is provided. The drilled product is manufactured by drilling a workpiece using the above-mentioned drill. The workpiece is made of the at least one of the composite material and the metal.