Abstract: A method of making a catheter is provided. The catheter has an atraumatic portion at the distal end of a catheter having the stiffness and torque resistance required of a catheter such as that suitable for angiographic uses, typically in French sizes on the order of about 2 to about 8. The atraumatic tip portion has a generally co-axially layered structure. An inner layer is made of soft atraumatic polymer, and an outer layer is made of a polymer to impart needed stiffness and torque properties to the catheter. In the preferred embodiment, a portion of the distal tip material of the harder outer layer is removed, thereby exposing the inner, atraumatic material for initial engagement with internal body passageways.

Abstract: A spinwelding procedure is provided for joining thermoplastic tubular members together at their respective axial ends. Axial end portions of very thin tubes are circumferentially supported both internally and externally, and one of the tubes is then rotated with respect to the other until adequate friction develops to melt the thermoplastic materials, after which they cool to heat bond together.