Abstract: A method and apparatus for manufacturing a lamina stack having laminas with a plurality of outer perimeter configurations. Each of the outer perimeter configurations has at least one common choke surface. The common choke surfaces form, when the laminas are stacked, a choke contacting surface on the outer perimeter surface of the lamina stack which extends continuously in the axial direction from the top lamina to the bottom lamina. The invention provides a method for manufacturing interlocked lamina stacks using a selectively actuated punches in a die assembly to stamp laminas with a plurality of outer perimeter configurations and to stack the laminas in a choke barrel with an alignment surface which cooperates with the common choke surface and securely holds the stamped laminas in position while the stack is being formed. Rotation of the choke barrel compensates for strip thickness variations.