A method for making a coaxial cable including an inner conductor, an outer conductor, and a dielectric material layer therebetween may include forming the inner conductor by at least forming a bimetallic strip into a tubular bimetallic layer having a pair of longitudinal edge portions at a longitudinal seam. The bimetallic strip may include an inner metal layer and an outer metal layer bonded thereto and coextensive therewith. Each of the longitudinal edge portions may be folded over. The method may also include forming a welded joint between adjacent portions of the folded over longitudinal edge portions and defining surplus material at the welded joint. The method may further include removing the surplus material at the welded joint and forming the dielectric material layer surrounding the inner conductor. The method may also include forming the outer conductor surrounding the dielectric material layer.