This paper describes the correlation between the elastic modulus, hardness and density of mainly X-ray amorphous TiAlxByNz (0.29 <= x <= 1.32; 1.15 <= y <= 2.07, 0.37 <= z <= 2.19) films, deposited by simultaneous reactive magnetron sputtering from TiAl and TiB, targets onto AISI 316 stainless steel and Si(100) substrates in Ar/N-2 mixtures at 150 degrees C. The elastic modulus, hardness and density were found to depend on chemical composition and the phases present, and an approximately linear correlation between elastic modulus and hardness could be established. The elastic modulus and hardness were also found to be a function of film density, except in films containing significant amounts of BN. (c) 2006 Elsevier B.V. All rights reserved.