Abstract: A box for cooling, by water circulation, the plating of blast-furnaces. This box comprises:a nose, directed towards the inside of the blast-furnace in the mounting position of the box, made from copper or from an essentially copper based alloy and defining at least one capacity for the cooling water provided with at least one water inlet and at least one water outlet,water delivery and discharge tubes connected respectively, on the one hand, to a water supply and to a water discharge and, on the other hand, to said water inlet and outlet of the nose, anda tubular steel body surrounding said tubes, and fixed sealingly to the nose.