NBSIR 75-730 Equilibrium Penny-Like Crack in Indentation Fracture B. R. Lawn and E. R. Fuller, Jr. Inorganic Materials Division Institute for Materials Research National Bureau of Standards Washington, D. C. 20234 September 1975 Interim Report for Period July 1, 1974 through June 30, 1975 Prepared for Department of the Navy Office of Naval Research Arlington, Virginia 22217