Stamping apparatus for forming hole with small diameter-length ratio in strip-like sheet metal, by forming through-hole using punch followed by forming die with recessing profile

摘要

A through-hole (3) is formed using a progressive die tool. In a first step, a punch (2) of diameter similar to that of the sheet metal thickness (a) is used. In a second step, a forming die (5) with a recessing profile is used concentric to the axis of the through-hole.