A drill head insert or drill head attachment, in particular a drill plate made of hard metal, for a rock drill, includes cutting edges (20, 20a) configured on the feed side which extend from a tip of the drill (18) rearward in a receding manner to an outer face (12, 14) of the drill plate (10). A drill plate (10) is substantially configured in the form of a roof when viewed from the side. A free face (24, 24a) at the cutting edge (20, 20a) abuts against a cutting face (22, 22a) along a substantial part of its extension between the tip of the drill (18) and the outer face (12, 14). A substantially smooth contour of the cutting edge (20, 20a) is interrupted by at least one projection (30, 30a, 30b) which projects beyond the cutting edge (20, 20a) in the feed direction.

A drill has a central axis, a front side, a circumferential surface, at least two main edges on the front side, which reach up to the circumferential surface and merge there with secondary edges, at least two central edges extending from the end of the main edge facing away from the circumferential surface, cutting surfaces associated with the main edges and central edges, chip flutes associated with the main edges and central edges and introduced into the circumferential surface, at least one cross edge adjoined by the ends of the central edges facing away from the main edges which passes through the central axis, a point thinning and chip run-up shoulders associated with at least the cutting surfaces of the central edges. An angle of the chip run-up shoulder decreases in the region of the point thinning towards the central axis as the distance from the front side increases.

Methods of forming a drill bit or boring tool having a cutting edge that includes a pair of generally smooth curvilinear shaped portions that are positioned near the radial outer portions of the cutting edge and connected to one another by a pair of generally linear portions that traverse a longitudinal centerline of the tool.

In a method for a finishing work of a spray-coated surface, an inner surface of a cylindrical hollow member is roughened by forming a helical groove thereon. A thermal spray coating is formed on the inner surface that is roughened, and a finishing work is carried out by cutting the thermal spray coating along a helix of the groove by use of a cutting tool. According to the method for a finishing work, a finishing work of a thermal spray coating with non-uniform hardness can be carried out efficiently.

A drill bit or boring tool having cutting edge that includes a pair of generally smooth curvilinear shaped portions that are positioned near the radial outer portions of the cutting edge and connected to one another by a pair of generally linear portions that traverse the longitudinal centerline of the tool.

The thread generating tool for producing a thread in a workpiece has the following features: a) the tool is rotatable about a tool axis (A), b) the tool has a number n1 of groove generating regions for generating in each case one groove in the workpiece and a number m1 of thread generating regions for generating the thread in the workpiece, c) each of the m thread generating regions is arranged behind one of the n groove generating regions as viewed in an axial projection parallel to the tool axis (A), and has a smaller extent than said groove generating region as viewed in cross section in the axial projection.

The present invention provides a beveling tool including: a body with a shaft hole formed through the center; a plurality of cutter blades arranged at predetermined distances on the circumferential surface of the body, each having a radial primary blade with a radial primary relief angle ranging from about 10 to about 20 degrees and a radial secondary blade with a radial secondary relief angle ranging from about 25 to about 35 degrees (or about 35 to about 45 degrees); discharge grooves formed longitudinally between the cutter blades to discharge chips produced in beveling; and a shank inserted in the shaft hole of the body, in which the body and the shank are connected by brazing. With the beveling tool of the present invention, it is possible to smoothly discharge chips produced in beveling and to prevent damage to the cutter blades.

A cutting head is formed for insertion into a support in a modular rotary tool, in particular a drill. It has a coupling pin onto which outer cover surfaces and torque surfaces are formed as clamping surfaces. The coupling pin has a particular circular groove, which divides the cutting head into a front pin part and a rear pin part. Stop surfaces for an axial pullout safety are formed in the transition area between the two parts. The torque surfaces and the clamping surfaces are arranged in different pin parts. The torque surfaces are preferably formed in the rear pin part.

Methods of fly-cutting a workpiece are disclosed, and in methods in which the position of a fly-cutting head or its associated cutting element is known as a function of time. Also disclosed are methods of forming features, such as grooves or groove segments, in a workpiece such as a cylindrical roll. The features may be provided according to one or more disclosed patterns. Articles made using tools machined in the manner described are also provided, such as polymeric film or sheeting that exhibit certain beneficial properties.

A general-purpose multiple-cutting edge drill includes: a drill point (1); a drill body (2); margins (3) located on an outer wall of the drill body (2); two lips, wherein, if viewed from an axial direction, from out to inside, each of the two lips successively includes an outer cutting edge (11), an arc cutting edge (12) and an inner cutting edge (13); a chisel edge (14); outer peaks (15) formed by intersection of the outer cutting edges (11) and the arc cutting edges (12); a center peak (16) formed by intersection of two inner flank surfaces and two split surfaces. Moreover, an included angle between the inner cutting edges (13) ranges from 108 to 128, an included angle between the outer cutting edge (11) ranges from 130 to 140, and an included angle between the inner cutting edge (13) and outer cutting edge (11) ranges from 28 to 40.