Essentials

May be made of plastics such as Lexan® or Plexiglas® Metal doors. Hollow metal can be either panel or flush, normally 1¾ inches (45 mm) thick. Flush consists of smooth metal face panels 1/20 inch (1 mm) thick. Vertical sheet metal ribs within door spaced 6 to 8 inches (150 mm to 200 mm) apart separate face panels ................
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