Steel Wire Rope&Accessories

Different applications for wire rope present varying demands for strength, abrasion and corrosion resistance. In order to meet these requirements, wire rope is produced in a number of different materials.

● Stainless Steel
This is used where corrosion is a prime factor and the cost increase warrants its use. The 18% chromium, 8% nickel alloy known as type 302 is the most common grade accepted due to both corrosion resistance and high strength. Other types frequently used in wire rope are 304, 305, 316 and 321, each having its specific advantage over the other. Type 305 is used where non-magnetic properties are required, however, there is a slight loss of strength.

● Galvanized Carbon Steel
This is used where strength is a prime factor and corrosion resistance is not great enough to require the use of stainless steel. The lower cost is usually a consideration in the selection of galvanized carbon steel. Wires used in these wire ropes are individually coated with a layer of zinc which offers a good measure of protection from corrosive elements. 

These elements are available in various models / designs, depending on the physical requirements of the steel wire rope and its intended application. A single strand can in certain cases be used quite properly as a steel wire rope.
A fourth component, that is equally as important for the steel wire rope's performance as the design and quality of the three basic components, is the lubrication of the core and the strands.

Steel wire
The minimum tensile strength of the steel wire defines the classification of the steel wire rope. The tensile strength of high quality steel wires in standard product range is as follows:
● Ungalvanised wires (mainly elevator cables)
1,370 N/mm² (140 kp/mm²).
● Zinc galvanised wires (mainly fishing)
1,570 N/mm² (160 kp/mm²).
● Zinc/alum. galvanised wires (mainly fishing)
1,570 N/mm² (160 kp/mm²).
● Stainless steel wires, tensile strength dependent on size
1,670 N/mm² (170 kp/mm²).
● Zinc galvanised wires (mainly industry)
1,770 N/mm² (180 kp/mm²).
● Zinc galvanised wires (mainly industry)
1,960 N/mm² (200 kp/mm²).
 

Strands
A strand is laid by a minimum of three wires that are arranged in many different designs (geometric patterns). The strand is almost always arranged around a centre wire. The wires are made from either steel or fibre (natural or man-made), or a combination of these.The quantity, size and material from which the individual wires are made characterise the rope and its qualities. Fewer, thicker wires create greater abra- sion resistance, whereas a greater number of thinner wires creates greater flexibility.
 

Core
Almost all steel wire ropes have a core. The core's function is to support and retain the strands in their respective positions while the steel wire rope is being used.
The core may be made of either steel, fibre, or a combination of the two. The core is usually one of the following types:
● FC (natural or man-made fibre, Fibre Core).
● WSC (steel core, Wire Strand Core). The WSC is a strand and is of exactly the same construction as the strands in the steel wire rope.
● IWRC (steel core, Independent Wire Rope Core). 

Steel wire rope is a versatile piece of equipment. In moorings, it can be used for motion control, stationkeeping, and vessel positioning, among other things.

Beyond moorings, it can be used for other tasks such as guidance, tie down, hold back, lifting, and many more. Compared to chain, steel steel wire ropes have a higher strength to weight ratio, making them easier to install and lighter on the floating structure.

Steel steel wire ropes are mostly commonly constructed of many thin steel wires wound into strands, which are then wound around a central core into the final steel wire rope. The most commonly used configuration for this type of wire construction is six strand. The number of strands and wires in each strand (e.G. 6 × 19, 6 × 36, 6 × 61) are governed by required strength, fatigue and bending stiffness requirements for each application. During selection consideration, it is important to note that this construction can generate torque as tension increases.

Steel wire rope can also be constructed of only individual wires tightly spaced and wound without stranding, known as spiral strand. This construction commonly uses a sheath for protection since it is much more susceptible to damage. To eliminate torque, the rope construction (spiral strand, half locked and full locked coils) uses layers of wires (or bundles of wires) wound in opposing directions to obtain the torque balanced characteristics.

Steel wire rope has a lower fatigue life and is more sensitive to damage and corrosion compared to chain. Steel wire rope segments in mooring lines are to be protected against corrosion attacks throughout the design life, either through coating of the strands or sheathing of the rope. Regular inspections are recommended throughout the design life to ensure the protection is intact and corrosion is within acceptable limits.

Termination connections also are available in various sizes to accommodate any size of mooring components. All steel wire ropes and components are certified and approved for use offshore by facilities managers. 

Combining strength with flexibility, steel wire rope helps operations of all sizes move heavy loads where they need to go with safety and ease.

Because every project has different requirements, various types of steel wire rope are designed and fabricated to serve different purposes. With a variety of orientations, strengths, and load capacities, it's important to know exactly which variety works best for your job. Here's a breakdown of the major categories.

● General purpose steel wire rope
The "class" of steel wire rope refers to the number of wires that compose a strand, as well as how many strands surround the core. For example, 6×31 FC steel wire rope consists of 6 strands containing 31 wires each, which are wrapped around a fiber core.
General purpose steel wire rope – the variety most commonly used for daily rigging operations such as lifting, overhead securement, pulling, and establishing tension – most often contains six strands and an independent steel wire rope core. Each of these strands can contain anywhere from 16 to 49 wires, with more wires increasing the flexibility of the rope.
General purpose steel wire rope can range in diameter from ¼ inch to 6 inches, with larger diameter ropes having breaking strengths of hundreds or even thousands of tons.

● Crane steel wire rope
Most cranes and some overhead lifting and securement devices require specialized steel wire rope that prevents the load from rotating. This is often achieved by having layers of compacted strands, oriented in a tightly-knit pattern around a core and layed in alternating directions.
Compacted varieties of crane steel wire rope provide increased fatigue resistance, strength, stability, and abrasion resistance. Often considered the strongest steel wire rope on the market, these types of steel wire rope are perfect for mining, industrial, construction, logging, and oilfield applications.

● Steel wire rope slings
Finally, in addition to customized lengths and types of steel wire rope, a qualified rigging equipment provider can also supply pre-fabricated steel wire rope slings. These slings are outfitted with eyes or sockets that affix the load to a lifting device. Steel wire rope slings come in dozens of orientations, sizes, and diameters, allowing for ultimate customization when outfitting your rigging operation.