We report on the nano-electron beam assisted fabrication of atomically sharp iron-based tips and on the creation of a nano-soldering iron for nano-interconnects using Fe-filled multiwalled carbon nanotubes (MWCNTs). High energy electron beam machining has been proven a powerful tool to modify desired nanostructures for technological applications and to form molecular junctions and interconnections between carbon nanotubes. Recent studies showed the high degree of complexity in the creation of direct interconnections between multiwalled and CNTs having dissimilar diameters. Our technique allows for carving a MWCNT into a nanosoldering iron that was demonstrated capable of joining two separated halves of a tube. This approach could easily be extended to the interconnection of two largely dissimilar CNTs, between a CNT and a nanowire or between two nanowires.