Abstract: The herein-proposed cutting tool comprises a spindle carrying the cutting element shaped as a solid of revolution, and a chip-breaker knife which, according to the invention is made likewise as a solid of revolution and set on the spindle rotatably round its geometrical axis so as to provide a clearance in between the knife blade and the surface of the workpiece being machined.

Abstract: A rotary cutting tool according to the invention comprises a supporting element secured in the tool body opposite to the cutting zone, said element interacting with the tool spindle and intended to load the spindle with forces which approach closely the cutting forces in magnitude but are opposite to them in direction. The rotary cutting tool according to the invention features high stiffness and resistance to vibration thereby ensuring higher accuracy, quality and efficiency of machining.

Abstract: The disclosed cutting-tool comprises a stepped-diameter arbor with bearings supporting rotatably thereon a holder carrying the cup-shaped cutting bit. In accordance with the invention, the holder is made up of a hollow shaft and a sleeve encompassing this shaft. The sleeve is journalled adjacent to the cutting bit in one of the bearings located about the stepped-diameter arbor, said arbor having a central bore. The other bearing is accommodated within the central-bore and supports the hollow shaft likewise accommodated in the central bore of the arbor. Owing to the disclosed structure of the holder and its interconnection with the stepped-diameter arbor, sufficient rigidity of the cutting-tool, matched by its compact size is ensured.

Abstract: The invention relates to methods of machining end faces with rotary tools. The method according to the invention comprises imparting to the workpiece a rotary motion and to the tool--a straight feed motion at an angle 20.degree.-75.degree. to the radius of the workpiece.