A device for deforming a shape memory alloy article, comprising: a. a slotted tubular mandrel comprising; i. a longitudinal axis and a first outer perimeter; ii. the tube having a length, a through lumen and a wall; iii. the lumen defining a first inner perimeter; iv. the tube having at least two slots through the wall; v. the slots being oriented essentially parallel to the tube longitudinal axis; vi. the slots extending partially along the tube length; vii. the tube having a first portion with an essentially constant first diameter; viii. the tube having a second tapered portion; ix. the second tapered portion having a varying diameter transitioning from the tube first diameter to a larger second diameter, wherein the second diameter is at least twice as large as the first diameter; and b. a translating device comprising; i. a rod sized to extend and slide through the slotted tubular mandrel through lumen; ii. an expander die coupled to the rod, wherein the expander die is configured to concentrically surround and advance over an outer surface of the slotted tubular mandrel and comprises at least two fins sized to extend and slide through said slots through the wall of the slotted tubular mandrel; c. a shape memory alloy article surrounding at least a portion of said slotted tubular mandrel. a. a slotted tubular mandrel comprising; i. a longitudinal axis and a first outer perimeter; ii. the tube having a length, a through lumen and a wall; iii. the lumen defining a first inner perimeter; iv. the tube having at least two slots through the wall; v. the slots being oriented essentially parallel to the tube longitudinal axis; vi. the slots extending partially along the tube length; vii. the tube having a first portion with an essentially constant first diameter; viii. the tube having a second tapered portion; ix. the second tapered portion having a varying diameter transitioning from the tube first diameter to a larger second diameter, wherein the second diameter is at least twice as large as the first diameter; and i. a longitudinal axis and a first outer perimeter; ii. the tube having a length, a through lumen and a wall; iii. the lumen defining a first inner perimeter; iv. the tube having at least two slots through the wall; v. the slots being oriented essentially parallel to the tube longitudinal axis; vi. the slots extending partially along the tube length; vii. the tube having a first portion with an essentially constant first diameter; viii. the tube having a second tapered portion; ix. the second tapered portion having a varying diameter transitioning from the tube first diameter to a larger second diameter, wherein the second diameter is at least twice as large as the first diameter; and b. a translating device comprising; i. a rod sized to extend and slide through the slotted tubular mandrel through lumen; ii. an expander die coupled to the rod, wherein the expander die is configured to concentrically surround and advance over an outer surface of the slotted tubular mandrel and comprises at least two fins sized to extend and slide through said slots through the wall of the slotted tubular mandrel; i. a rod sized to extend and slide through the slotted tubular mandrel through lumen; ii. an expander die coupled to the rod, wherein the expander die is configured to concentrically surround and advance over an outer surface of the slotted tubular mandrel and comprises at least two fins sized to extend and slide through said slots through the wall of the slotted tubular mandrel; c. a shape memory alloy article surrounding at least a portion of said slotted tubular mandrel.