Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a drilling tool having a large drill, in particular a core drill, in which a center drill is guided in an axially flexible or movable manner, with the axial movement of said center drill relative to said large drill being limited by at least one limit stop, wherein at least one pin that is supported on the large drill, the shaft thereof or a transition therebetween, extends toward the center drill, and the pin (24) is formed at an attachment body (26) comprising a contact surface (46) that abuts on a counter contact surface (52) of the drilling tool (10) and in particular has at least partially a larger lateral extension than the pin.

Abstract: The invention relates to a drilling tool having a large drill, in particular a core drill, in which a center drill is guided in an axially flexible or movable manner, with the axial movement of said center drill relative to said large drill being limited by at least one limit stop, wherein at least one pin that is supported on the large drill, the shaft thereof or a transition therebetween, extends toward the center drill, and the pin (24) is formed at an attachment body (26) comprising a contact surface (46) that abuts on a counter contact surface (52) of the drilling tool (10) and in particular has at least partially a larger lateral extension than the pin.