... used in power plants,chemical plants,oil refinery,iron or steel works,machine factories,paper mill,cement mills,medicine plants and foodstuff ... :F-plain style(may be committed in the symbol of steel grating)S-serrated styleI-I-section style4)Sign of surface ... galvanizing(may be omit-ted in the symbol of the steel grating)P-PaintedU-Untreated Industrial park ,Anping,County,hebei,China ...