1.1 ,This specification covers the manufacture and purchase requirements of products used for assembly and construction of circular reinforced corrugated steel manholes used in sewer and water works. Products covered by this specification are not normally used for the conveyance of sanitary or industrial wastes. The steel sheet used in fabrication of the manhole structures has a protective metallic coating of zinc (galvanizing), aluminum, 55 % aluminum-zinc alloy, or zinc-5 ,% aluminum-mischmetal alloy, or a polymer pre-coating.