HITPERM-type alloys were investigated to determine the influence of boron, zirconium and hafnium content on magnetic softness, and to find the crystallisation temperature allowing one to obtain the lowest coercive field, H c . The second crystallisation stage temperature decreases with the increase of B content, suggesting that boron impairs the stability of the two-phase structure at high temperatures. The addition of Hf improves thermal stability, better than Zr. After annealing for 1h, H c of the alloys after the optimum heat treatment is between 17 and 26A/m. The lowest values of H c are obtained for the alloys with Hf only.