The present work focuses on the squeezing effect, which is a commonly observed phenomenon during the surface generation in ultra precision diamond turning. Different from the conventional modelling of orthogonal and oblique cutting processes, an analytical model and a finite element model are proposed to investigate the squeezing effect along the radial direction of the surface profile. The simulation results reveal that the squeezing effect is more significant than other factors, such as lateral material swelling and recovery for the specific work material and tool geometry. ; Department of Industrial and Systems Engineering