It had been reported that B has beneficial effects on the magnetostriction of anisotropy compensated Dy0.7 Tb0.3 Fe2 alloys. In the present work, Dy0.7 Tb0.3 Fe1.95 and Dy0.7 Tb0.3 Fe1.95 Bx (x=0.1, 0.15, and 0.2) alloys, in the form of 8 mm diameter cylindrical rods, were investigated both in the as-cast and zoned conditions. At 5 kOe dc magnetic field, magnetostriction of ∼1200 and 900 microstrains was observed for zoned samples with x=0 and 0.1, respectively. For zoned samples with x<0.1 and for the as-cast sample of the parent alloy, magnetostriction of ∼500 microstrains was measured. X-ray diffraction of the zoned x=0 and x=0.1 samples showed a strong prevalence of the 〈112〉 and the 〈110〉 grain orientations; in contrast, the other samples appeared to possess a random grain orientation. Optical and scanning electron microscopy studies revealed a significant increase in the volume fraction of the R Fe3 phase with increasing boron content. This increase in the volume fraction of the (Tb,Dy) Fe3 phase and the reduction in the desired grain orientation of the (Tb,Dy) Fe2 phase are attributed to be the reasons for the large decrease in the magnetostriction of the (Tb,Dy) Fe1.95 alloys with boron addition. © 2007 American Institute of Physics.