A piston having a body member made from plastic material adapted for mounting to a piston rod for axial movement with the piston rod in a hydraulic cylinder under high working pressure conditions is disclosed. The plastic piston body member has a first axial end portion, an opposite second axial end...http://www.google.com.au/patents/US5941162?utm_source=gb-gplus-sharePatent US5941162 - Piston
