Abstract: A door sill has a substrate having a recessed upward open channel formed therein, an extruded aluminum deck that at least partially receives the substrate, at least one threshold cap, an interior face cap that covers a portion of the substrate, and a lock key. A first portion of the threshold cap is coupled to the extruded aluminum deck. A second portion of the threshold cap is positioned in the recessed upward open channel adjacent a portion of the interior face cap. A portion of the lock key is press fitted intermediate the second portion of the threshold cap and the portion of the interior face cap. A seal is formed between the second portion of the threshold cap and the interior face cap. The seal is positioned proximate the inside wall of the upward open channel formed in the substrate above the bottom surface of the upward open channel.