Abstract: Disclosed is an edge for a tool and/or for an insert to be removably and/or fixedly mountable on a tool. The edge is formed at a meeting of a first surface and a second surface comprises at least one segment extending from a first peak to a second peak through a nadir interposed therebetween. The first peak has a first peak line passing therethrough, the second peak having a second peak line passing therethrough, and the nadir having a nadir line passing there-through. The first peak line, the second peak line, and the nadir line are parallel to each other, and a first depth D1 between the nadir line and the first peak line is greater than a second depth D2 between the nadir line and the second peak line.

Abstract: A composition for a ceramic cutting tool which enjoys long tool life at high speed machining of ferrous alloys. The composition consists essentially of 60-80% alpha aluminum oxide (Al.sub.2 O.sub.3) having a hexagonal crystal structure and the remainder of titanium carbonitride (TiCN). The titanium carbonitride has a mixture of 30-70% titanium carbide and the remainder titanium nitride. The mixture is compacted and hot pressed, sintered or pressure sintered to form the tool.

Abstract: A ceramic cutting tool is disclosed in which the cutting tool consists essentially of a hot pressed composition of alumina and 6 to 30% by weight of aluminum nitride. This ceramic cutting tool is particularly advantageous for cutting ferrous materials, especially cast iron.

Abstract: A chip breaker arrangement in cutting tool inserts comprising chip breaking grooves that vary in width, depth and/or distance from the cutting edge cyclically, with the variations occurring at either fixed or varying frequencies while the cutting edges are formed in a straight line along the varying chip breaking grooves whereby the same inserts provide effective chip control over a wide range of cutting conditions.

Abstract: A sintered hard metal product, e.g. a disposable cutting insert for use in the machining of metals, consisting of a cemented metal carbide substrate and a thin wear-resistant surface coating comprising a plurality of coating layers of different compositions applied on to at least a part of the surface of said substrate and on top of each other by chemical vapor deposition, characterized in that said coating layers include:an innermost layer applied directly onto said substrate and consisting of at least one member selected from carbides, nitrides and carbonitrides of Ti, Zr, Hf, V, Nb, Ta, Al and Si;a second layer applied directly on said innermost layer, consisting essentially of aluminium oxide and having a thickness of about 1 to about 3.mu.; anda third layer composed of one or more sublayers of titanium carbide, titanium nitride and titanium carbonitride, applied on top of said aluminium oxide layer.

Abstract: A cutting insert of the disposable kind and which can be used to provide positive rake cutting action when mounted in a negative rake tool holder and having a chip control structure comprising successive descending and chip deflector surfaces effective over a broad range of operational conditions namely a wide range of materials cutting depths and feed rates and such that along every radial section line directed centrally through and in the direction of a central portion of the insert no surface is directed upwardly with respect to a preceding surface while along every section line directed normally with respect to a cutting edge of the insert at least one deflector surface slopes upwardly with respect to or is substantially parallel to a base surface.