EN
The paper refers to magnetic properties of the (Fe_{80}Nb_{6}B_{14})_{1-x}Tb_{x} (x=0.06 and x=0.08) bulk nanocrystalline alloys prepared using the vacuum suction casting technique. The samples were in the form of rods with diameters of d=1.5 mm, 1 mm and 0.5 mm. It was shown that for the alloys with x=0.08 the significant magnetic hardening with the decrease of sample diameter was observed. For d=0.5 mm the coercive field equals 2.46 T and the maximum energy product |JH|_{max}=77.2 kJ/m^{3}.