The invention relates to an abrasive insert comprising a layer of PCD or PCBN; and a cemented carbide substrate to which the layer of PCD or PCBN is bonded through an interlayer; the interlayer comprising a bonded mass of superhard abrasive particles and refractory particles wherein an average size of the superhard abrasive particles is the same as or less than that of the refractory particles and to a method of manufacture of the insert.