Galvanized steel nylon-coated wire rope with 7x7 standard construction is commonly used in pulleys, and in aircraft and automotive controls. This wire rope is black-colored for ease of recognition. Galvanized steel wire rope is coated with a thin layer of zinc that protects the underlying material from corrosion and provides rust resistance. This strong material remains ductile over long work periods, and has a higher breaking strength than stainless steel. A nylon coating is very strong, lightweight, and flexible, has excellent abrasion-resistance, and resists crushing and cracking. 7x7 strand core has seven strands of wire rope with seven wires in each strand formed helically around a strand core. 7x7 strand core is stronger but less flexible than 6x19 and 6x36 class constructions.
Wire rope, also called wire cable, is an assembly of wire strands formed helically around a central core. It is used for pulling, lifting, rigging, hoisting, and motion-control applications most commonly found in the manufacturing, marine, oil, mining, fiber-optics, aircraft, automotive accessory, and construction industries. A combination of characteristics including material, finish, construction, diameter, length, and breaking strength combines to give each rope its performance ability. Wire rope materials are selected for properties such as strength, elasticity, conductivity, and chemical- and weather-resistance. For strength purposes, most wire rope is made of bright (uncoated or bare) wire. However, it is also produced in a variety of finishes, such as polypropylene (PE), vinyl (PVC), or nylon. These coatings can increase overall durability and strength, and allow for specific use. The breaking strength for wire rope is the strength at which new wire rope will fail under a stationary load. Breaking strength is not considered safe working load (SWL) limit.