Method of making valve guide by forming a not hollowed compact by uniaxial pressure perpendicular to its longitudinal axis

摘要

A powder metallurgy method for making valve guides for use in internal combustion engines advantageously utilizes uniaxial side pressing to form compacts. Such compacts are subsequently sintered, formed into a cylindrical shape, and then hollowed to form a valve guide. The valve guides exhibit improved uniformity and density and hardness from end to end of the valve guide when contrasted to powder metal valve guides formed with uniaxial end pressing.