An adjustable die for manufacturing tubular twist beam parts, comprising: an upper half including a punch extending between opposite ends and having a convex profile for engaging a metal tube; said upper half including a pair of upper cassettes, each upper cassette providing a groove and being disposed along one end of said punch, said grooves of said upper cassettes being axially aligned with one another; a lower half including a pair of lower cassettes vertically aligned with said upper cassettes, each lower cassette providing a groove, said grooves of said lower cassettes being axially aligned with one another and facing said grooves of said upper cassettes; said lower half including a pair of form blocks being disposed on opposite sides of said punch for moving toward one another and engaging opposite sides of the metal tube; said lower half including a pair of side cams, said side cams being disposed on opposite sides of said form blocks and outwardly of said form blocks for pressing said form blocks toward one another and the metal tube; characterised in that at least one of a vertical spacer block and a pair of horizontal spacer blocks, wherein said vertical spacer block extends between said upper half and said lower half for restricting movement of said upper half toward said lower half and each of said horizontal spacer blocks are disposed between one of said lower cassettes and the adjacent form block for restricting movement of the adjacent side cam toward said form block; and wherein said at least one of said vertical spacer block and said pair of horizontal spacer blocks are removable and replaceable with a vertical spacer block and a pair of horizontal spacer blocks of a different dimension. an upper half including a punch extending between opposite ends and having a convex profile for engaging a metal tube; said upper half including a pair of upper cassettes, each upper cassette providing a groove and being disposed along one end of said punch, said grooves of said upper cassettes being axially aligned with one another; a lower half including a pair of lower cassettes vertically aligned with said upper cassettes, each lower cassette providing a groove, said grooves of said lower cassettes being axially aligned with one another and facing said grooves of said upper cassettes; said lower half including a pair of form blocks being disposed on opposite sides of said punch for moving toward one another and engaging opposite sides of the metal tube; said lower half including a pair of side cams, said side cams being disposed on opposite sides of said form blocks and outwardly of said form blocks for pressing said form blocks toward one another and the metal tube; characterised in that at least one of a vertical spacer block and a pair of horizontal spacer blocks, wherein said vertical spacer block extends between said upper half and said lower half for restricting movement of said upper half toward said lower half and each of said horizontal spacer blocks are disposed between one of said lower cassettes and the adjacent form block for restricting movement of the adjacent side cam toward said form block; and wherein said at least one of said vertical spacer block and said pair of horizontal spacer blocks are removable and replaceable with a vertical spacer block and a pair of horizontal spacer blocks of a different dimension.