The local deflection of the wheel-workpiece contact is one of the major factors influencing the size accuracy of a ground surface. This paper presents a study of the local wheel-workpiece contact deflections using single-grain cutting on soft and hard steels under conventional grinding conditions. Instead of the commonly used disc-mounted grits, single grains on an actual grinding wheel have been employed to more closely reflect the elastic behaviour of the grinding wheel. The harder steel was found to produce larger normal forces on the grain, which in turn resulted in higher grain-workpiece deflections. Effort has been made to determine the various components of deflections including that due to grain rotation by tangential force. Implications on the determination of wheel-work contact deflections are also discussed in view of this new mechanism of local contact deflections.