Mould and a method of its manufacture

A method of producing a mold for composite casting of a one piece cast tool, which includes at least a first portion which defines a working component of the tool and which is manufactured from steel, and a second portion which defines a body component of the tool and which is manufactured from grey iron, there being at least one interconnection zone between the steel and the grey iron, comprising

• producing more than one first model section in correspondence with the first portion,
• producing a second model section in correspondence to the second portion,
• providing each of the more than one first model section and second model section with more than one planar contact surface along which they are brought into contact with one another,
• finishing the mold with a molding material,
• positioning the mold in a casting position in which the more than one contact surface is in a horizontal position, the more than one contact surface representing, in the mold, the interconnection zone, and in which the more than one first model section is positioned below the second model section, wherein all contact surfaces lie in a common plane.