Patent ID: 8627905

Claim:
A cutting element having a longitudinal axis extending towards a direction, the cutting element comprising: a substrate comprising a periphery and an interface surface having a radial direction and a circumferential direction; and an ultra hard material layer formed over the substrate and having an interface surface having a radial direction and a circumferential direction, wherein one of the interface surface of the substrate and the interface surface of the ultra hard material layer comprises: a first annular section comprising an outer band and extending along the direction to a first level; a second section located radially inwardly of the first annular section and extending along the direction to a second level; a plurality of spaced-apart projections arranged in an annular row and at least a portion of each of the plurality of spaced-apart projections is located radially inward of the outer band and extending along the direction beyond said first and second levels; and a circumferential groove bisecting an upper surface of each projection, wherein each circumferential groove has a depth extending to a level that is spaced apart along the direction from said first and said second levels.