A refractory to be used repeatedly or for a long period of time, such as a refractory for casting, especially a nozzle for casting and an SN plate, has improved tolerance. The refractory for casting contains Al.sub.4O.sub.4C in the range of 15 to 60% by mass, both inclusive, an Al component as a metal in the range of 1.2 to 10.0% by mass, both inclusive, and a balance including Al.sub.2O.sub.3, a free C, and other refractory component; a sum of Al.sub.4O.sub.4C, Al.sub.2O.sub.3, and the Al component as a metal is 85% or more by mass; and a content of Al.sub.4O.sub.4C (Al.sub.4O.sub.4C), a content of the Al component as a metal (Al), and a content of the free carbon (C). The contact of the free carbon satisfies the following Equation 1 and Equation 2:

1.0C/(Al.sub.4O.sub.4C0.038+Al0.33)(Equation 1)

and

1.0C/(Al.sub.4O.sub.4C0.13+Al0.67)(Equation 2).

A refractory to be used repeatedly or for a long period of time, such as a refractory for casting, especially a nozzle for casting and an SN plate, has improved tolerance. The refractory for casting contains Al.sub.4O.sub.4C in the range of 15 to 60% by mass, both inclusive, an Al component as a metal in the range of 1.2 to 10.0% by mass, both inclusive, and a balance including Al.sub.2O.sub.3, a free C, and other refractory component; a sum of Al.sub.4O.sub.4C, Al.sub.2O.sub.3, and the Al component as a metal is 85% or more by mass; and a content of Al.sub.4O.sub.4C (Al.sub.4O.sub.4C), a content of the Al component as a metal (Al), and a content of the free carbon (C). The contact of the free carbon satisfies the following Equation 1 and Equation 2:

1.0C/(Al.sub.4O.sub.4C0.038+Al0.33)(Equation 1)

and

1.0C/(Al.sub.4O.sub.4C0.13+Al0.67)(Equation 2).

Provided is a refractory product which is not impregnated with pitch or the like, wherein it has higher corrosion-erosion resistance and thermal shock resistance as compared to a refractory product subjected to pitch or the like-impregnation treatment. The refractory product which is not impregnated with tar or pitch is characterized in that, in terms of values of physical properties of a sample of the refractory product as measured after heat-treating the sample in a non-oxidizing atmosphere at 1200 C.: an apparent porosity is 7% or less; a total void volume of pores having a pore diameter of 1 m or less is 80% or more of an integrated void volume of pores of the entire sample of the refractory product; and a gas permeability is 5010.sup.17 m.sup.2 or less.

Provided is a refractory product which is not impregnated with pitch or the like, wherein it has higher corrosion-erosion resistance and thermal shock resistance as compared to a refractory product subjected to pitch or the like-impregnation treatment. The refractory product which is not impregnated with tar or pitch is characterized in that, in terms of values of physical properties of a sample of the refractory product as measured after heat-treating the sample in a non-oxidizing atmosphere at 1200 C.: an apparent porosity is 7% or less; a total void volume of pores having a pore diameter of 1 m or less is 80% or more of an integrated void volume of pores of the entire sample of the refractory product; and a gas permeability is 5010.sup.17 m.sup.2 or less.