Fabricated building components of metal, namely, metal castings, in either raw or finished machined condition, used in the construction of submarines, ships and other watercraft, fitted either directly into the vessel or as components assembled into more complex pieces of equipment; common metals and their alloys; copper, nickel and chrome alloys, including, but not limited to, the alloy def stan 02-824; metal materials for building and construction, namely, metal castings; metal castings.