DuuMuut 20” Cast Iron Manhole Cover and Frame, Black Septic Tank Lid with Base, Round Sewage Basin Cover, Heavy Duty Flat Cover/Lid for Corrugated Pipe or Riser (True Diameter 19.7 in)

Description

Ductile iron is placed outdoors as a normal oxidation process, once the oxidation layer is formed on the surface, it will not penetrate into the interior, the oxidation layer will be isolated from the air and will no longer rust, after all, ductile iron will not be rusted like iron will be peeled off layer by layer rust is gone.