Biocompatibility testing of metallic materials should include implantation of particulate material of high purity and small size. Powder production of iron-, cobalt-, and titanium-based implant metal alloys was achieved by a method of gentle rubbing of metal bars in closed containers of the same material. Suspensions were prepared for injection via a thin needle. Tissue reactions to the metal particle suspensions were evaluated up to one year after injection into various host tissues of rats. Tests for improvement of the vehicle were performed. A recommendation is given for metal powder production and for two compatible and resorbable vehicles for suspension of powders.