Development of net-shaping technology for the undercut stem of the high-strength bolt

摘要

A type of bolt that has an undercut in its stem portion is used for fastening engine parts. In the past, the range in which the stem could be net-shaped was limited. We recently developed a "spiral filling upsetting method" that has completely eliminated the machining process while expanding the range in which the net-shaping process can be applied. we focused on the three-dimensional spiral buckling characteristic, which is not ordinarily utilized in plasticity processing, and effectively applied it on this technology.