Direct measurement of the deformation field associated with the creation of a machined surface shows that the strains in the surface and chip are large and essentially equal. This is supported by microstructure and hardness data. By interpreting these results in the framework of an upper bound model for the deformation, control of severe plastic deformation parameters on the machined surface is seen to be feasible, suggesting interesting opportunities for nano- and microscale engineering of surface microstructures by machining.