The plate is one solid piece of military-grade aluminum block that has been machined to accept the Anchor and is surface mounted to the door with four 3/16 in. x 1/2 in. stainless steel or titanium screws. These screws (and their holes) do not violate the integrity of the fire door. The plate is 1⁄2 in. thick and weighs 14.9 oz. The melting point of the aluminum plate is 933.57 K and aluminum burns at over 4,100 K which is well beyond the fire resistance of the fire door it is installed in. The plate is attached to the bottom of the door where fire temperatures are typically cooler.