Abstract: A fusible element having an ability to withstand a large number of on-off cycles is provided. The element comprises a ribbon of copper without any M-effect causing means. The element is bent in a zig-zag shape to establish a plurality of contiguous planar sections enclosing obtuse angles with each other and forming straight edges of the loci of intersection of the planes defined by the planar sections. The straight edges are non-perforated to maximize their flexure strength. Each of the planar sections is provided with at least one point of reduced cross-section remote from the straight edges. The ribbon of copper is electro-plated with sulfamate of nickel forming a dull, ductile layer of nickel.