The influence of tensile stress annealing on the magnetic properties of amorphous alloys is reported for ribbons belonging to the pseudo ternary system (FeCoNi)
75Si
15B
10. Ribbons of compositions (Co
1-xFe
x)
75Si
15B
10are susceptible to stress annealing in the whole composition range

. A very large easy ribbon axis anisotromy can be produced in the range

whereas the largest hard ribbon axis anisotropy is producable in the composition range around x=0.15. Ribbons of compositions [CO
1-x(Fe
0.5Ni
0.5)
x]
75Si
15B
10are found susceptible to stress annealing only in the range

. In all the compositions the induced easy ribbon axis anisotropies are irreversible whereas the hard ribbon axis anisotropies are recoverable with activation energies ≥ 1.55 eV.