Cast iron can't keep up. Americast® is our revolutionary alternative to cast iron that's more durable, 50% lighter and costs less to install. This traditionally styled, integral-apron bathtub features a beveled headrest, lumbar support and a StanSure slip-resistant surface. Alcove installation. Americast® is our proprietary, revolutionary alternative to cast iron that's more durable, 50% lighter and costs less to install. Thanks to inherent manufacturing advantages, Americast® bathtubs can be made deeper, flatter and roomier than their cast iron counterparts.