The present invention provides a method of manufacturing a flexible tube. The method includes the steps of providing a source of material to be extruded and forming a tubular member with an extrusion die. The extrusion die includes a radially and outwardly extending tooth configured to define a protrusion upon the outer surface of the tubular member. The method further includes the step of rotating the tubular member after exiting the extrusion die such that the protrusion forms a helical profile along the length of the tubular member.
