The Bethlehem Steel trade name for a patented sheet steel having a hot-dip coating of corrosion resistant aluminum-zinc alloy. The Galvalume sheet coating consists of an alloy of nominally 55% aluminum, 1.6% silicon, and the balance zinc by weight, as listed in ASTM designation A792. On a volume basis, the coating is approximately 80% aluminum. GALVALUMEĀ® is a registered trademark of BIEC International Inc.