Abstract: A method for joining bodies by melting down a joining element. The joining element acts on a surface of one of the bodies and penetrates the surface as a result of a directed force. Once in a penetrated condition, a mechanical excitation is generated such that during further penetration of the joining element into the one body, the advance is maintained through the directed force and the melting down is maintained through the mechanical excitation. Molten or melted material is hydraulically displaced into the bodies.

Abstract: A harpoon nail having two or more sets of teeth on opposite sides of fingers that deform while penetrating the framing members. The teeth engage with a bottom surface to fasten the framing members together. A piercing nail having sets of teeth on two edges penetrates through framing members and the teeth engage with a bottom surface to fasten the framing members together. A piercing nail with a spring member that deforms as the nail penetrates through framing members engages with a bottom surface to fasten the framing members together. A self-locking nail having two members that move relative to one another when penetrating through framing members fastens the framing members together.