A Milled tooth bit with a wear and fracture resistant surface

A milled tooth bit (Figure 1, 14) comprises a steel bit and at least one extending leg (Figure 1, 13), and a steel cone (Figure 1, 12) rotatable on its leg (Figure 1, 13). At least a portion of the bit (Figure 1, 14) has a cermet composite wear-resistant surface 24 disposed thereon. A material microstructure (Figure 4, 26) comprising several cermet regions (Figure 4, 28) distributed in a ductile matrix (Figure 4, 30) may be provided. Each cermet region (Figure 4, 28) can comprise a composite of hard grains (Figure 4, 32) and a ductile phase (Figure 4, 34) bonding the grains. The grains are chosen from carbides containing W, Ti, Mo, Nb, V, Hf, Ta and Cr. The ductile phase (Figure 4, 34) is chosen from Co, Ni, Fe and/or their alloys, and alloys with materials chosen from C, B, Cr, Si and Mn. The ductile metal matrix (Figure 4, 30) separates the cermet regions (Figure 4, 28) from each other and is formed from the group consisting of steel, Co, Ni, Fe, W, Mo, Ti, Ta, V, Nb and/or their alloys, and alloys with materials chosen from C, B, Cr and Mn. A braze layer may also be provided between the surface portion of the tooth 22 and the cermet material layer 24. The unsintered green-state part of the cermet material layer 24 may be applied in the form of a cap corresponding to the profile of the tooth 22.