Patent ID: 7905432

Claim:
A casting nozzle having a molten steel flow hole portion, in which a plurality of independent members comprising at least one of protrusion portions and concave portions discontinuous in both directions parallel and perpendicular to a molten steel flowing direction are disposed, wherein each of said protrusion portions or the concave portions has a size satisfying expressions: H>2 mm L> 2× H in which H is a maximum height of the protrusion portion or a maximum depth of the concave portion, and L is a maximum length of a base portion of the protrusion portion or the concave portion, to prevent a flow of the molten steel from stagnating in the molten steel flow hole portion, wherein the independent members make an inner surface area of the molten steel flow hole portion rough so that an inner diameter of the molten steel flow hole portion becomes variable over the inner surface of the rough area, the casting nozzle is an immersion nozzle, and the base portions of the independent members are spaced apart from one another by portions of a flat surface of the inner surface area of the molten steel flow hole portion.