Patent ID: 8186460

Claim:
A segmental hard material insert for a working tool, comprising a planar polycrystalline diamond layer ( 13 ) having, in a layer plane thereof, a single main cutting element ( 16 , 36 ) and a contact edge ( 15 ) which is straight at least in some regions and is located opposite the main cutting element, the main cutting element ( 16 , 36 ) having two, facing outwardly, convex cutting sections ( 17 , 27 ; 37 , 47 ) and a smooth, facing outwardly, concave transitional region ( 19 ; 39 , 49 ) connecting the two convex cutting sections ( 17 , 27 ; 37 , 47 ) and providing a smooth transition between the convex cutting sections and the transition region, with the apex ( 20 ; 40 ) of the transitional region ( 19 ; 39 , 47 ) being located on a central line of the main cutting element ( 16 ; 36 ).