Abstract: A method for making a C-shaped magnetizable core powdered material manufactured by filling a predetermined quantity of the powdered material into a C-shaped mold having two open ends one end being smaller than the other open end and having a trapezoidal cross section, compressing said powdered material to a density of at least 6.0 g/cm.sup.3 by a cooperating, C-shaped ram and a combined C-shaped closure-ejector element; the C-shaped ram entering the larger opening and moving toward the smaller opening which is closed by said closure-ejector element, withdrawing the ram and ejecting the core from the die with said closure-ejector element moving from the smaller opening toward the larger opening whereby the trapezoidal sides of the core are released simultaneously whereby the core uniformly expands in all directions as it is ejected from the die to produce a core having a uniform density and of improved structural, magnetic and electrical properties.