Abstract: A method of hardening by plastic deformation surfaces of articles shaped as continuous helical coils and having essentially round cross-section by means of deforming elements wherein said deforming elements are arranged at the opposite sides of said article for forced rotation in engagement with the surface of the material of said article, while said article is rotated about its longitudinal centerline and subjected to ultrasonic oscillations. The deforming elements are rotated in opposite directions so as to form on the surface of said article a regular microrelief in the form of an intersecting mesh-like pattern. By changing the ratio between the angular rotational velocities of the deforming elements, a microrelief of desired geometry is attained.

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 herein-proposed method of cutting solids of revolution by a rotary tool having circular cutting lip resides in that the tool is imparted feed motion, while its rotation results from the interaction of said tool with the rotating workpiece being machined. Prior to bringing the tool in contact with the surface being machined the tool is imparted a positive rotation at a speed differing by not more than 20 percent from the tool working speed, in the same direction as the tool working motion. The rotary tool for carrying said method into effect is shaped as a solid of revolution having a circular cutting lip and held on a spindle provided with a through center bore for the stream of coolant to feed therethrough, the screw-type wind turbine being provided in said spindle bore.

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.