Abstract : The purpose of the M.I.T. research on wear during the calendar year 1977 was to apply the delamination theory of wear in minimizing the wear rate of splines and door hinges. The technique explored was the use of thin soft metal coatings on hard substrates, which was shown in a prior study to increase the wear resistance by three orders of magnitude. One of the problems concerning the use of thin metal coatings in these applications was the possible removal of the coated material by oxides on splines and salts formed on door hinges. Therefore, two-pronged investigations were undertaken in collaboration with NADC and Foxboro/Trans-Sonics, Inc: the realistic evaluation of soft metal coatings and the role of abrasive wear in these applications. This report describes the work done on the basic abrasive wear mechanisms, in particular the size effect of abrasive particles on abrasive wear.