A step bit according to some embodiments includes a body including one or more flutes having a cutting edge configured to cut a hole in a workpiece, and a plurality of steps provided on the body. The steps progressively increase in diameter from a first distal step to a terminal proximal step. One or more of the steps have first and second lands. An outer diameter of the first land is less than the outer diameter of the second land. A length of the first land is less than a length of the second land.

The invention relates to a drill comprising a body which extends along a longitudinal axis (L) from a rear side (B) to a front side (F), wherein the body comprises a main cutting edge on the front side (F), wherein the body comprises at least one guide bevel which extends in axial direction (A) and toward the front side (F), wherein, toward the front side (F), the guide bevel has an end section which is tapered. The invention further relates to a method for producing such a drill.

The invention relates to a method for producing a guide bevel on a workpiece, in particular a cutting tool. The workpiece to be machined is clamped in a clamping device which is rotationally driven about a rotational axis, and at least one laser unit is provided. The clamping device and the laser unit can be moved relative to each other by means of at least one CNC-controlled axis. The laser unit is of a type that is suitable for machining the workpiece by removing material. In order to produce the margin, the laser unit and the clamping device are controlled such that the workpiece in the clamping device is continuously rotated about the rotational axis of the clamping device at least by a specified angular amount while the laser unit and the clamping device are moved relative to each other at least by a specified distance in order to remove material from the workpiece so as to produce the guide bevel.

In a drill, a negative land is provided on a rake face, and a ridge line at an intersecting position of the negative land and a flank face, a ridge line at an intersecting position of the flank face and a margin, and a ridge line at an intersecting position of the negative land and the margin are convex faces in a longitudinal rectangular cross section. When a curvature radius of the convex face of a first ridge line at the intersecting position of the flank face and the negative land is 1, at curvature radius of the convex face of a second ridge line at the intersecting position of the flank face and the margin is 0.8 to 1.5 times the curvature radius of the first ridge line, and a curvature radius of the convex face of a fourth ridge line at the intersecting position of the negative land and the margin is 1.5 to 3.0 times the curvature radius of the first ridge line.

A drilling system and methods provide stability and cutting performance to produce holes having desired straightness and other characteristics. The system may include a cutting head provided with a central cutting system and first and second side cutting inserts. The tool provides a major diameter with the OD cutting margins on the replaceable side inserts, as well as possibly cutting margins on the center cutting member. Adjustment mechanisms may be provided to adjust the center cutting member and/side cutting inserts.

The drill of the present invention includes: a drill main body; a chip discharge flute extending from a tip flank face of the drill main body toward a rear end side of the drill main body and formed on an outer circumference of a tip part of the drill main body; a margin formed at an opposite side of the chip discharge flute in the drill rotation direction; and a body clearance formed at an opposite side of the margin in the drill rotation direction and having an outer diameter smaller than that of the margin. A surface roughness of the body clearance at least along a circumferential direction is equal to or less than a surface roughness of the margin.

A drill bit for use in forming holes in a printed circuit board (PCB) is disclosed. The drill bit includes a drill bit body having: a drill bit tip at a first end of the drill bit body; a flute winding about the drill bit body in a helix, wherein a helix angle of the flute is between 44 and 46 degrees in the vicinity of the first end and increases with increasing distance from the first end to between 49 and 51 degrees; and a land width of between 0.08 and 0.1 millimeters.

A drill bit for use in forming holes in a printed circuit board (PCB) is disclosed. The drill bit includes a drill bit body having: a drill bit tip at a first end of the drill bit body; a flute winding about the drill bit body in a helix, wherein a helix angle of the flute is between 44 and 46 degrees in the vicinity of the first end and increases with increasing distance from the first end to between 49 and 51 degrees; and a land width of between 0.08 and 0.1 millimeters.

A drill with a drill flute (12) includes symmetrical fluted lands (20) helically extend around a core, wherein grooves (18) remain between the fluted lands, said grooves having a width (72) that exceeds the spine thickness or width (24) of the fluted lands (20), and wherein the grooves (18) comprise a convex core reinforcement (22) at the groove bottom thereof. The width (24) of the fluted lands (20) at the drill head side end (16) is smaller than at the shank side end (14) of the drill helix (12), and at least increases in certain areas. The core reinforcement (22) at the drill head side end (16) is more convex than at the shank side end (14), thus has larger radii (40, 42).

A drill head for deep-hole drilling includes cutting blade tips brazed to cutting chip discharge ports opened on a head distal end surface, guide pads mounted on a plurality of positions of the circumferential surface at the head distal end side, and a hollow inside portion made into a cutting chip discharge passage communicating with the cutting chip discharge ports. A guide pad portion having an arc surf ace that slide-contacts with the inner circumference of a cutting hole is formed on the outer end surface of the circumferential portion cutting blade tip.