Tooling assembly and method for explosively forming features in a thin-walled cylinder

A method of explosively forming a helical tube from at least one thin-walled cylinder using a tooling assembly, the method comprising the steps of:

• inserting the at least one thin-walled cylinder into a die of the tooling assembly, the die surrounding the at least one thin-walled cylinder and comprising an interior surface that defines a helical thread pattern having peaks and valleys, wherein a taper axis is defined between two peaks of the thread pattern, and wherein the taper axis diverges radially outwardly as the die extends axially outwardly;
• surrounding the at least one thin-walled cylinder and the die with a casing of the tooling assembly, wherein a cavity is defined by the at least one thin-walled cylinder and extending along an axial centerline of the tooling assembly;
• positioning an explosive charge within the cavity;
• at least partially submerging the tooling assembly;
• and
• detonating the explosive charge, whereby the at least one thin-walled cylinder is formed into a helical tube that corresponds with helical thread pattern of the interior surface of the die.