Abstract: A steel mold has a mold body with a molding surface and heat-conducting members with a first and a second end embedded in the mold body. The heat-conducting members have a length and a thickness and are made of a material having a melting point above 950.degree. C. The heat-conducting members are spaced at a distance from the molding surface wherein a ratio of the thickness to the distance is 1:1 to 1:3 and wherein the length is 3 to 10 times the thickness. A cooling system is embedded within the mold body whereby one of the ends of the heat conducting members is connected to the cooling system.