Abstract: A wire rope including a core rope having a number of strands each made of a number of wires, and a number of outer strands closed on the core rope. Each strand of the core rope has a contact section where two or more wires of the strand of the core rope come into contact with the closed outer strand. A total of contact section rates Tz is 20 percent or more of a circumference of a circumscribed circle of the core rope: Tz (%)=Ti/C.times.100, wherein Tl denotes a length of a circumferential component of the contact section, "C" denotes a length of the circumference of the circumscribed circle of the core rope. A non-contact section rate Gz is below 20 percent of the circumference of the circumscribed circle of the core rope: Gz (%)={100-(n.times.Tz)}/n, wherein "n" denotes the number of strands.

Abstract: A steel material for colored springs is formed with a metallic deposit on the surface. The metallic deposit contains copper, zinc, and chromium. In an annealing process, copper and zinc diffuse in the deposit to exhibit a gold color tone while chromium is oxidized to exhibit a dark gray color tone. The combination of these color tones exhibits a beautiful black color tone which is distinguishable from a normal spring. The deposit improves the formability in the spring shaping process.

Abstract: Facilitating the distinction among different spring steel products and at the same time improving their surface appearance and corrosion resistance by plating the surface of said different spring steel products before spring-forming with either alternate layers of Cu and Zn or alternate layers of Ni, Cu and Zn, the amount of Cu and Zn differing for steel products differing in size and/or material, to obtain color-developable spring steel products, drawing and taken coil spring-forming the resulting plated spring steel products, and low temperature annealing said resulting plated spring steel products to develop their colors, the colors being different for spring steel products differing in size and/or material, whereby mixing and erroneous assembly of spring steel products differing in size and/or material is prevented.