Method of forming an interlocking metal joint

摘要

A metal structure such as a tube having an axial seam formed with interlocked tongues and recesses with in-plane stabilization created by locally moving areas of the metal out of plane to form dimple-like structures ("dimples") either before or after forming the tongues and recesses. After the tongues and recesses are interengaged, the dimples are flattened to cause the out-of-plane metal to return to the plane so that the metal adjacent to them is moved strongly laterally, and the walls of the tongues and recesses make a strong abutting fit against one another which resists relative out-of-plane displacement, thus providing "in plane" stabilization.