US Patent 10005118 Method for joining components made of high-strength steel

A method for the joining of hollow profiles made from high-strength steel, in particular to form a motor vehicle frame, the hollow profiles being connected to one another, nonpositively and positively against being pulled out, by pinching (crimping) in a connection zone, one end of at least one of the hollow profiles having a connection zone for pinching which is soft at least during forming. This soft connection zone may be hardened during pinching if at least one of the profiles to be joined is made from hardenable steel and is brought to austenizing temperature before pinching.