Abstract: A steel-reinforced door including a sheet metal framework, strengthened with a plurality of metal structural sections, to which a lock and bolts are fitted, the metal sheet also acting as support for a plurality of mechanisms designed for the operation of the bolts, the steel-reinforced door being mounted on a frame via hinges, and closing due to the effect of the bolts which engage with holes made in the frame. The door includes a first element designed to allow the door to be opened either inwards or outwards, maintaining its function as a steel-reinforced door, the first element including a second metal sheet (10), connected to the sheet metal framework (4) so as to form, with the framework (4), a closed structure suitable to house the lock (8) and the bolts (9, 9a), and the mechanisms designed to operate the bolts (9, 9a).