MAKING AN ELONGATED PRODUCT

摘要

An elongated product is formed such that first a core (2) is formed, the outer surface of the core (2) being made of plastic. Thereafter, a tubular metal layer (4) is extruded such that the layer (4) is seamless. When the metal layer (4) is extruded, a clearance is allowed between the metal layer (4) and the core (2). After the metal layer (4) has cooled, the diameter of the metal layer (4) is reduced such that the metal layer (4) contacts the plastic core (2). Thereafter, the metal is annealed such that the flexibility of the metal layer (4) increases.