The extreme pressure properties of fluorides and silicofluorides as lubricants for titanium were studied using the Falex tester. With water solution of sodium fluoride and water soluble metallic and nonmetallic silica-fluorides, jaw loads of 1500 lb were attained without welding. Use of ceramic blocks in the Falex tester showed the efficacy of the fluorides and silicofluorides in preventing excessive metal build up on the ceramic blocks, or excessive wearing away of the ceramic blocks. Sodium fluoride was superior to potassium or ammonium fluoride, and ammonium silicofluoride was the best of the silicofluorides when combined with sodium fluoride.