Abstract: A rock drill for rotary hammers is proposed in which a conveying helix (3) having main and secondary webs (6 to 9) is used. A one-piece carbide crown, with its wing-shaped main and secondary lips (24 to 27), is butt-welded to the conveying helix.

Abstract: A rock drill for rotary hammers is proposed in which a conveying helix (3) having main and secondary webs (6 to 9) is used. A one-piece carbide crown, with its wing-shaped main and secondary lips (24 to 27), is butt-welded to the conveying helix.

Abstract: The invention proposes a drilling tool, in particular rock-drilling tool for rotary and/or percussive operation, in which, for the purpose of improving the drilling properties, the drilling-dust discharge groove is subdivided into at least two discharge-groove sections, each section having its own drilling-dust-carrying surface.

Abstract: A rock drill which has a cutting tip of roof-shaped design at its front end is proposed. In order to achieve a reduction in the loading of the carbide cutting tip or an increased drilling capacity in particular in concrete, the flanks are subdivided into flank sections in order to achieve a slimmer embodiment of the drill head.

Abstract: A drilling tool, especially for the rotary percussion drilling of preferably rock, has a drilling body equipped toward the drilling side preferably with cutting bits, and with an axially arranged bore for receiving an exchangeable centering drill. In order to achieve axial movability and a reliable rotational takeup of the centering drill in the drilling tool, the drilling tool has a transverse bore which is arranged centrally relative to its drill longitudinal axis and into which can be inserted a bar-shaped or tubular holding means which centrally penetrates a corresponding recess on the shank of the centering drill so that the centering drill can be moved in the axial direction.

Abstract: A drilling tool, in particular for rotary percussion drilling preferably of rock, is proposed, with a drill body preferably equipped with cutting tips toward the drilling side and with an axially arranged bore for receiving an exchangeable center drill. In order to carry out easy mounting and demounting of the center drill, the drilling tool is designed in two parts, the center drill being capable of being introduced into the drilling tool on the clamping side.