A binary electrical fuse (13) is comprised of a core wire (20) which is preferably relatively rigid, has a high ohmic resistance, and a high melt temperature. The core wire is clad with a metal (21) of substantially less rigidity having a low ohmic resistivity, and low melt temperature, i.e. in the range of from about 230 degrees C to 700 degrees C. The resistance of the core wire is at least about ten times the resistance of the cladding and preferably twenty or more times the resistance of the cladding. In the course of a fusing cycle the cladding metal will melt and pool, leaving the core wire as the sole conductor resulting in a rapid blow of the fuse due to the sudden high resistance load presented by the core wire.