and 9 this embodiment also includes a central planar region 126 bounded by an outer groove 128 the complete trace 121 of outer groove 128 is illustrated in phantom outer groove 128 defines an upper 129 and lower 130 inner boundary defining a height u201c h u201d and a radius u201c r u201d the lower inner boundary is located at the lowest level in groove 128 and in some instances may be at the periphery in this embodiment the intersection between groove 128 and central planar region 126 defines a step 127 terminating in an outwardly sloping bevel 125 in such a fasion the thickness u201c h u201d and width u201c r u201d of the trace of groove 128 are foreshortened additional desired thickness at the cutting edge 131 is therefore rendered possible while still addressing issues of compressive stresses still other embodiments are illustrated at fig1 13 in fig1 the cutting element 140 is comprised of a substrate 142 and an abrasive layer 144 in this embodiment the substrate 142 includes an exterior groove 149 which defines an arcuate intersection boundary 147 with an internal planar region 148 the phantom trace 146 of a conventional groove is illustrated the use of arcuate or curvilinear intersection 147 serves to foreshorten radius u201c r u201d and thickness u201c h u201d again resulting in stress reduction thereby results in a further reduction in compressive and combination stresses while still providing maximum thickness of the abrasive compound at the cutting edge 143 the cutter 150 of fig1 comprises a.