Titanium, argon, nitrogen, and iron were implanted in separate strips on a ferritic AISI E52100 cylinder. Three implant energies were chosen to obtain a continuous distribution from the surface to a depth of 120 nm and total doses were 4.1017ions cm−2. The friction coefficient and wear track topography were measured by sliding against a martensitic AISI 52100 steel ball in air, in a fully formulated lubricant and in highly purified hexadecane. In dry sliding, titanium reduced the friction coefficient to 0.32 and suppressed the near-surface cracking, [in agreement with previous work at Harwell and Naval Research Labs]. In hexadecane, titanium reduced the friction coefficient to 0.22, iron and nitrogen increased, it to 0.7 from 0.55, and all implants decreased wear. In the fully formulated lubricant, only the break-in pattern was modified. Auger measurements showed that carbon penetrated the material with all implants, creating TiC in the Ti-implanted strip and probably strengthening the other implanted areas by carbide precipitates and compressive stresses.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference in Washington, D.C., October 5–7, 1982