Results on scratch testing of hybrid, organic-inorganic coatings are reported. The behavior of the friction coefficient as well as the load of cracking, delamination and chipping are analyzed using spheres of different radii. The effects of a variation of the loading and displacement rate are tested. Models to predict the friction coefficient are tested and related to the observations. The apparent fracture toughness and its relationship to the deformation of the coating and substrate are discussed. Parameters are given that art: independent of the indenter radius and coating thickness and, therefore, permit an objective assessment of the failure of coatings.