Pivotal hammer type impact testers are used in an experimental study of repetitively impacted lubricated contacts. Various steels are used in one- and two-body wear modes; the rate process of wear is investigated with respect to the impact parameters (normal and tangential approach velocity), and lubricant viscosity. For normal impact, a boundary lubrication system forms, but superimposed sliding speeds with a viscous lubricant tend to create an elastohydrodynamic lubrication (EHL) condition, greatly resisting wear. Approximate measurable wear equations are derived for cylindrical striking surfaces.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Montreal, Canada, October 8–10, 1974