REINFORCED C-SHAPE STEEL FOR ENCIRCLING AND MANUFACTURE THEREOF

PURPOSE:To permit the title C-shape steel to withstand the number of winding and unwinding of more than 200,000 times by a method wherein a composite layer, consisting of a thermoplastic synthetic resin or a thermo setting synthetic resin and a metal, is formed on the surface of the Cshape steel by coating laminate sandwich (extrusion molding). CONSTITUTION:A steel material, capable of being provided with resilient property, is proper for the material of a C-steel 1 and, especially, hardened hoop is the optimum. A thermosetting synthetic resin or a thermoplastic synthetic resin is employed for a synthetic resin for forming the composite of synthetic resin on the surface of the steel material by coating laminate sandwich or the like while the thermoplastic synthetic resin between them is suitable for mass producing. Stress is concentrated at both ends 2, 3 of the C-shape steel, which form the openings of the C-shape steel 1, when they are formed into slit edges 5 and the frequency of winding and unwinding is increased whereby cracks may be readily generated on both ends 2, 3, however, the endurance can be increased when they are formed into round edges 6, further, the endurance may be increased further when the openings of the C-shape steel are provided with skirts 4.