Abstract: A cutting insert for use on a milling machine including an element formed of hard material, such as carbide. The element defines a rear face, by means of which it may be mounted in position, and a front face. The front face defines, towards its lower edge, a cutting projection defining a single leading cutting edge. The front face defines a surface, which may be a curved surface, which extends rearwardly and upwardly from the cutting edge. When the cutting insert is located in abutment with an adjacent cutting insert, the upper edge of the planar front face is located immediately adjacent a forwardly extending part of the undersurface of the cutting projection of the next adjacent cutting insert.