Patent ID: 7931856

Claim:
A method of forming a bushing comprising the steps of: providing a compaction die having internal walls forming an internal opening, the internal opening having a bottom and a top, providing a lower punch having exterior walls forming an exterior surface that generally corresponds to the internal opening of the compaction die, the lower punch entering the bottom of the internal opening in the compaction die, the lower punch having interior walls that form an internal opening, providing an upper punch having exterior walls forming an exterior surface that generally corresponds to the internal opening of the compaction die, the upper punch entering the top of the internal opening in the compaction die, the upper punch having interior walls that form an internal opening, providing a lower core rod having exterior walls forming an exterior surface that generally corresponds to the internal opening in the lower punch, the lower core rod including interior walls forming an interior opening, the lower core rod having a top surface, providing an upper core rod having exterior walls forming an exterior surface that generally corresponds to the internal opening in the upper punch, the upper core rod having a bottom surface, introducing a metal powder into the internal opening of the compaction die, and compacting the metal powder to form a powder metal blank by having the lower punch and the upper punch enter the internal opening in the compaction die, and by having the lower core rod and the upper core rod enter the compaction die in a manner such that the top surface of the lower core rod and the bottom surface of the upper core rod approach each other such that an axial opening is formed in the powder metal blank, wherein the lower core rod includes a generally flat section, on its exterior surface which generally flat section is tapered from the top surface of the lower core rod downwardly to an intersection with an exterior wall section to form the generally flat section.