A cutting element, insert or compact, is provided for use with drills used in the drilling and boring of subterranean formations. This new insert, in its preferred embodiment, has a "hoop" region of polycrystalline diamond extending around the periphery of the compact to reduce the residual stresses...http://www.google.com/patents/US6408959?utm_source=gb-gplus-sharePatent US6408959 - Polycrystalline diamond compact cutter having a stress mitigating hoop at the periphery
