A simplified form of the theoretical single‐ion, crystal field contribution to the magnetocrystalline anisotropy of RE 2TM17 compounds is given. Through an evaluation of this contribution in Sm2(Co1−xFex)17 compounds, two methods of favourably altering their anisotropy were suggested. The first involves substitution of Sm by Tb in order to compensate the adverse influence of Fe beyond x?0.2. The expected effect is observed. Substitution of Co by Mn or Cr was used in an attempt to avoid the consequences of structural features of the Fe‐containing alloys upon the anisotropy. These new compounds yield up to 40% improvement in the anisotropy, and at high magnetizations, compared to Sm2Co17.