Improvements in or relating to elements faced with superhard material

摘要

A preform element, such as a cutting element for a drag-type drill bit, includes a facing table (22) of superhard material having a front face (23), a peripheral surface, and a rear surface (27) bonded to a substrate (21) which is less hard than the superhard material. The rear surface of the facing table is integrally formed with a plurality of ribs (25) which project into the substrate (21) and extend in directions outwardly away from an inner area of the facing table towards the peripheral surface thereof.