Abstract: A cylindrical cutting element for a cutting machine which includes base ps arranged at a uniform distance from each other. A chisel holder which receives an exchangeable chisel is secured with respect to each base element. The chisel holder has a plug connector which allows the chisel holder to be inserted into a plug receiver of the base element, where it is held by a pressure screw on the base part that grips the plug connector. To relieve the plug connector from the forces acting on the chisel, the base part has a projection which extends in an approximately parallel direction to the running direction of the cutting element and a stop that follows the projection in the running direction and forms an angle therewith. The stop limits the insertion of the chisel holder into the base element and absorbs forces transmitted through the chisel to the chisel holder.

Abstract: The invention relates to a round shaft bit with a bit head and a bit shaft, n which the bit shaft has a circumferential groove with a longitudinally slotted clamping sleeve positioned therein, and in which the bit shaft with the clamping sleeve placed under tension can be axially fixed in a bore of a bit holder whereby the bit shaft remains freely rotatable in the clamping sleeve.

Abstract: An apparatus for holding a tool in machinery and having a tool holder contable to the machine, with a cylindrical receptacle into which the cylindrical shaft of a tool is inserted rotatably and removably. The tool holder is detachably and rigidly connectable by an improved self-locking dovetail connection to a base plate which is rigidly connected to the machine. The base plate or the tool holder is provided in the area of the dovetail connection with arrest serrations running transverse to the insertion direction and on the opposing tool holder or base plate, oriented adjacent to the arrest serrations, there is installed a spring-loaded holding bolt or a stop spring which engages either with the arrest serrations of the base plate or of the tool holder, respectively, and enhances the connection between the base plate and the tool holder.