Abstract: A burnisher for use with a lathe or production machine to burnish opposing thrust faces of a crankshaft laterally fixed and rotatably driven thereby. The tool of the burnisher has a plurality of opposing burnishing rollers that operatively engage under opposing torsional load thrust faces of the crankshaft rotatably driven by the lathe or production machine. The burnisher features biasing spring construction that provides for the movement of the burnishing tool laterally into a centered working position relative to the opposing surfaces of the crankshaft when sufficient turning force or torque is applied to the burnishing tool. This construction provides for even application of burnishing force by the burnishing rollers onto the thrust faces for application in which the workpiece is fixed laterally without becoming distorted.