Abstract: A sintered hard metal body composed of at least one carbide as tungsten carbide and a binder phase consisting essentially of cobalt and/or nickel, the hard metal body being provided with a boronized surface zone having a thickness of 1-100 .mu.m characterized in that the hard metal contains small additions of up to about 5 percent by volume of the hard metal body of cubic carbides as VC, TiC, TaC, Mo.sub.2 C, ZrC, NbC and/or Cr.sub.3 C.sub.2, the content of binder phase is 6-40% of the volume of the body, and the mean grain size of the tungsten carbide is 0.2-1.5 .mu.m. The process of forming said body is also disclosed.