Abstract: A cutting tool, for cutting a workpiece of a non-ferrous metal with hard particles dispersed therein, includes a rake face, a relief face, and a cutting edge formed at the intersection of the rake face and the relief face. A distal end portion of the cutting tool including the cutting edge is composed of a diamond tip. The relief face is divided into a first relief face and a second relief face with a curved boundary ridge therebetween. The first relief face intersects the cutting edge, and the second relief face extends from the boundary ridge away from the cutting edge. A first relief angle, that is an angle between the first relief face and the rake face of the cutting tool, is larger than a second relief angle that is an angle between the plane of the second relief face and the rake face. The boundary ridge is formed on the diamond tip.

Abstract: A cutting tool for cutting a lead-free copper-based bearing alloy containing 75 to 95% by mass Copper(Cu):, 1 to 15% by mass Bismuth(Bi), and 1 to 10% by mass hard particles comprising metal phosphide, boride, or carbide. The Cutting tool includes a rake surface, a clearance surface, and a cutting edge formed on a line of intersection between the rake surface and the clearance surface. A tip end site including the cutting edge comprises a diamond tip, and the diamond tip comprises a sintered body formed by sintering diamond particles having an average particle diameter (D50) between 0.2 ?m and 1.6 ?m. The cross section of the cutting edge preferably has a curved surface shape with a radius of curvature between 10 ?m and 50 ?m.

Abstract: A front cover affixed to the pump impeller of a torque converter, provided with a flat annular flat annular surface to be engaged with the clutch disk of a direct-coupling clutch formed within the torque converter.The flat annular surface is formed in a flat and annular surface having a hard and compact metallographic structure by rolling a rolling tool made of a extremely hard material on the flat annular surface under a pressure and by thus causing plastic deformation of the flat annular surface. An intermediate part of an arcuate section of a small radius is formed between the periphery of said flat annular surface and a connecting part adjacent to the flat annular surface.

Abstract: A method of grinding an annular surface into a flat annular surface, in which a front cover for a torque converter is formed by means of press-forming and the thus press-formed front cover is supported floatingly on a supporting table and pressed against an annular grinding stone to be ground.

Abstract: A fluid torque converter equipped with a direct-coupling clutch comprising a front cover fixed to the pump impeller of the fluid torque converter, and a clutch disk axially slidably mounted on the output shaft of the fluid torque converter and disposed between the front cover and the turbine runner.A friction plate affixed to a friction surface formed on the front cover is divided into two portions, namely, a radially outer portion made of a frictional material having a large coefficient of dynamical friction and a large heat capacity and a radially inner portion made of a frictional material having a large coefficient of statical friction and a high compressive strength.