Results are reported on the magnetic properties of (R65Fe35)100−xBxglasses, where R denotes Y, Gd, and Er, and x is 10 or 20. Curie‐Weiss fits were made to high temperature susceptibility data to determine average effective moments per magnetic ion and Weiss temperatures. Hysteresis loops and modified Arrott plots were used to determine the spontaneous magnetizations, coercive forces, and ordering temperatures. The effective moments and spontaneous moments are compared with those calculated on the assumption of local moments on both magnetic subnetworks, and assuming various spin structures. There is evidence for moment instabilities on Fe atoms in the Y‐Fe‐B glass, depending on local‐environment effects. Local random anisotropy plays an important role in Er‐Fe‐B but not in Gd‐Fe‐B.