A drill structure includes a shank part and a flute part arranged on one end of the shank part. A chisel edge is formed on the front end of the flute part and two drill blades with tilt directions toward the shank part are symmetrically formed on the two sides of the chisel edge. Every drill blade includes: a primary relief surface with a cutting edge, a first connecting edge and a first chamfering edge, a secondary relief surface with a knife-back edge, a second connecting edge, a second chamfering edge and an outer edge, and an assist relief surface. The second connecting edge joins to the first connecting edge, and the second chamfering edge connects with the first chamfering edge. The assist relief surface, which tilts toward the shank part the, is extend from the first chamfering edge and the second chamfering edge. This drill structure can improve the surface finish of the drilling hole.

Proposed is a drilling tool for drilling workpieces, having a tool tip and a basic body and a core, wherein the basic body has at least one main groove as at least one helical depression, for the purpose of realizing a conveying helix in each case. For the purpose of prolonging the service life, the core, in a first portion that starts at the tool tip and/or extends to the tool tip, has a constant cross-sectional area perpendicular to the axis of rotation and, in an adjoining second portion, counter to the direction of advance, has a cross-sectional area that increases, at least in portions.

A drill structure comprises a shank part and a bit part. A web is formed on the front end of the bit part. Two sides of the web are tilted backward to form two cutting faces. At least one flute (chip-discharge groove) is formed on the surface of the bit part. Each cutting face includes a primary cutting face and a secondary cutting face. The thickness of the prismatic web edge of at least one primary cutting face is smaller than the outer-side width of the primary cutting face. An auxiliary cutting face is extended to the wall of the flute from the cutting edge of the primary cutting face and a portion of a blade back of the secondary cutting face of another cutting face. The present invention decreases the drilling resistance during drilling a hole and increases the service life of the drill bit.

A rod includes a first rod section occupying a predetermined region in a longitudinal direction, and a second rod section occupying a region different from the first rod section in the longitudinal direction. The first rod section has composition including A% by mass of cobalt, 0 to 1% by mass of chromium, 0 to 0.5% by mass of vanadium, and remainder of tungsten carbide and unavoidable impurities. The second rod section has composition including B% by mass of cobalt, 0 to 1% by mass of chromium, 0 to 0.5% by mass of vanadium, and remainder of tungsten carbide and unavoidable impurities. Contents of cobalt in the first rod section and the second rod section satisfy a relationship of 1% by massB<A20% by mass. The second rod section has a length of 10 to 1000% with respect to the first rod section in the longitudinal direction.

A drill structure comprises a shank part and a flute part disposed on one end of the shank part. The front region of the flute part has a web. Two sides of the web are tilted backward to form a first cutting face and a second cutting face. At least one flute is formed on the outer surface of the flute part. The flute part has a bit core in the center thereof. The radius of the cross section of the bit core is defined as the web thickness. The first cutting face includes a first primary cutting face and a first secondary cutting face. The second cutting face includes a second primary cutting face and a second secondary cutting face. The first cutting edge of the first primary cutting face is not parallel with the first connection edge. The width of the primary cutting face width is larger than the web thickness. The drill structure has high cutting ability and long service life.

The present invention discloses an industrial high speed micro drill that is made to access remote and inaccessible locations in order to blend, grind, polish and cut materials and parts as determined by visual inspection powered via a pneumatic power source. The high speed drill is deployed by a controlled, articulating guide tube that acts in a multidirectional fashion to direct the action of the assemblage and allow for discrete manipulation of the pneumatically powered drill while harboring a channel and pneumatic power source carrying rubber tubing.

The drill (1) is provided with a drill body (2) having a rotation center axis (O), two cutting edges (3) provided on the tip side of the drill body (2), and chip evacuation flutes (10) provided behind the two cutting edges (3) in the direction of rotation of the drill (1) from the two cutting edges, the drill tip angle () being from 170 to 190, the web thickness (d) being from 0.10 to 0.25 times the drill diameter (D), the opening angle () of the chip evacuation flutes (10) being from 85 to 110, and the drill (1) comprising a curve having a radius of curvature that gradually decreases from the cutting edge side wall surface (14) to the heel side wall surface (15) of the chip evacuation flutes (10) in a cross-section at a position where the chip evacuation flutes (10) are present.

Miniaturized deburring and/or chamfering tool with a cylindrical guide sleeve (2) in which a blade holder base body (5) is arranged in an exchangeable manner, which has at least one receiving slot (20) for receiving and guiding a blade (6) arranged there, which is leaf-shaped and designed so that it can bend along its longitudinal axis, and which, at its free front end, has a cutting head (7) with a deburring or chamfering blade arranged there, wherein an internal cooling of the blade (6) and removal of shavings from the blade (6) are achieved by the fact that the coolant flows around the blade (6) in the receiving slot (20) on at least two facing sides.

A combined drill and chamfer tool (13, 21) for producing boreholes (29) in a workpiece (28) and for subsequently producing a chamfer (30) on at least one bore edge of the borehole (29), comprising a drill bit (1), which is secured in a rotationally fixed manner in a base body (3), and at least one chamfering blade (4) arranged behind the drill bit (1) in the axial direction, said chamfering blade being mounted in a blade window (25) arranged in the drill shank (35) and spring-loaded so as to be displaceable transversely to the longitudinal axis of the combined tool (13, 21), wherein the drill body (13) comprising the drill bit (1) and the drill shank (35) is made of a solid hard metal material, and wherein a spring-loaded, displaceable control bolt (5) is located in a central longitudinal bore (36) of the solid hard metal drill, the front tip (15) of said bolt controlling the transverse displacement of the chamfering blade (4), which is transversely displaceable within the blade window (25).

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.