Improvement in or relating to elements faced with super-hard material

摘要

A preform element, such as a cutting element for a rotary drag-type drill bit, includes a facing table (20) of superhard material having a front face (23), a peripheral surface(29), and a rear surface (27) bonded to a substrate (21) which is less hard than the superhard material. The rear surface (27) of the facing table is integrally formed with a plurality of ribs (25, 26) which project into the substrate (21), and at least major portions of the ribs extend across the rear surface of the facing table in directions which are generally radial with respect to at least one point (28) which is adjacent or outside the peripheral surface (29) of the facing table. IMAGE