1-3/4" (44.4 mm) insulated full flush design - rated for light to extra-heavy-duty use. Polystyrene core provides insulation characteristics and resistance to impact Core is chemically bonded to face sheets providing total surface support Mechanically interlocked, hemmed vertical edges or stitch-welded seamless edge for added strength and rigidity 7 gage (4.2 mm) steel hinge reinforcements Inverted end channels welded to both face sheets for added stiffness.
