Samples Of Sm2Fe17Nx having the Th2Zn17 structure were prepared using mechanical alloying and subsequent heat treatment. The magnetic behaviour is found to depend significantly on heat treatment temperature. Coercive forces of up to 31.3 kOe at 300 K have been measured from hysteresis loops with maximum applied fields of 50 kOe. At 423 K the coercive force was 17 kOe. The variations of coercive force, magnetization and remanence as functions of maximum applied field are consistent with the view that the magnetization of this material is pinning controlled.