This paper describes a system for haptic object categorization. It consists of a robotic hand, the LUCS Haptic Hand I, together with software modules that to some extent simulate the functioning of the primary and the secondary somatosensory cortices. The haptic system is the first one in a project at LUCS aiming at studying haptic perception. In the project, several robotic hands together with cognitive computational models of the corresponding human neurophysiological systems will be built. The haptic system was trained and tested with a set of objects consisting of balls and cubes, and the activation in the modules corresponding to secondary somatosensory cortex was studied. The results suggest that the haptic system is capable of categorization of objects according to size, if the shapes of the objects are restricted to spheres and cubes.