To provide die parts made of cements carbide, excellent in impact resistance, plastic deformation resistance, wear resistance, and coercive force and suitably used for a punching die in particular, and also to provide press worked parts, particularly lead frame, worked by using the above.
In the die parts made of cemented carbide, containing a hard phase composed essentially of tungsten carbide and a binding phase composed essentially of cobalt, the binding phase is regulated to 6-14 wt.% of the cemented carbide and the average grain size of tungsten carbide is regulated to 2.5-4.5 μm and further, the content of fine-grain tungsten carbide of <1.0 μm grain size is regulated to ≤5 area % based on the whole tungsten carbide. The press worked parts can be obtained by performing working by the use of the above.
ITO KAZUE
ENOMOTO CO LTD