Adhesiveless direct bonding between polymeric tubular members assembled with an interference fit using an oxidative cold gas plasma treatment, and implantable medical leads manufactured in part using a cold gas plasma bonding process are disclosed. An illustrative method includes subjecting a number of polymeric tubular members to an oxidative cold gas plasma, creating an oxygen rich layer on each of the tubular members. The treated surfaces of the tubular members are assembled together, forming a direct bond along an overlapping region between the tubular members when in conformal contact with each other.