Zn-5Al mischmetal coated steel strand, 1x7, 3.0mm to 8.0mm, for tension cable that has to survive salt air and industrial atmosphere without regular attention. Plain zinc coating protects steel sacrificially, but it consumes itself doing so. Add about five percent aluminium and a trace of mischmetal to the coating and the corrosion product that forms at a damage point is different: it is denser, it stays in place, and it keeps the anodic reaction local instead of spreading