PURPOSE: To produce a hard pit tip excellent in wear resistance and toughness at a low cost by fusing lumpy polycrystalline bodies of diamond or cubic BN polycrystalline on a substrate with a specified self-fluxing alloy as a binder.

CONSTITUTION: Lumpy polycrystalline bodies of diamond or high hardness cubic BN polycrystalline are fused on a superhard substrate with a self-fluxing Ag-Cu or Ni alloy having ≤1,200°C m.p. as a binder to produce a pit tip or a cutter tip used for excavating, piercing or drilling soil, rock, etc. This product much more excellent in wear resistance and toughness than the conventional cemented carbide or diamond sintered compact and adaptable even to a complex required shape is easily obtd. at a relatively low cost.