Abstract: In a bottom-pouring casting apparatus having a holding tank, a ladle in the tank and a tank cover, which seals the ladle in the tank, a pouring tube and holding casting are disclosed for mounting on and through the tank cover to provide the pouring tube in the molten metal of the ladle, which tube and holding casting are have similarly tapered outer and inner walls for mating at assembly thereby utilizing gravity and mechanical pressure on the tube holding assembly to more tightly secure the tube agains the holding casting to avoid driving the tube from the holding casting and rendering it inoperable.