What is the strongest type of steel cable?

The commodity that “holds up” the rigging, lifting, and overhead securement industries is indisputably wire rope. Combining strength with flexibility, wire rope helps operations of all sizes move heavy loads where they need to go with safety and ease. Without enough properly tested and verified wire rope on hand, the output and productivity of the entire plant can grind to a standstill.

Because every project has different requirements, various types of 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 Wire Rope

The “class” of 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 wire rope consists of 6 strands containing 31 wires each, which are wrapped around a fiber core.

General purpose 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 Wire Rope Core (IWRC). Each of these strands can contain anywhere from 16 to 49 wires, with more wires increasing the flexibility of the rope.

General purpose 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. For a detailed wire rope strength chart, consult our catalog here.

Crane Wire Rope

Most cranes and some overhead lifting and securement devices require specialized 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. For example, the Oliveira NR Maxipact PPI contains 18 outer strands, forming wire rope that can be effectively implemented in a non-rotating environment at temperatures from -50°C to +80°C. 

Compacted varieties of crane wire rope provide increased fatigue resistance, strength, stability, and abrasion resistance. Often considered the strongest wire rope on the market, these types of wire rope are perfect for mining, industrial, construction, logging, and oilfield applications.

Other rotation resistant varieties come in 19×7 and 8×19 classes with an IWRC; for more detailed information, view the wire rope strength chart and select Wire Rope > Crane.

Wire Rope Slings

Finally, in addition to customized lengths and types of wire rope, a qualified rigging equipment provider can also supply pre-fabricated wire rope slings. These slings are outfitted with eyes or sockets that affix the load to a lifting device. Wire rope slings come in dozens of orientations, sizes, and diameters, allowing for ultimate customization when outfitting your rigging operation. Check out the catalog or connect with a rigging equipment professional for guidance and to place your custom order

Discover the Strongest Wire Rope with Southwest Wire Rope

The professionals at Southwest Wire Rope have been serving the needs of the rigging, overhead lifting, and securement industries with an unwavering dedication to quality and excellence since 1966. If you are in the market for industry-leading lifting gear, or need your system inspected by a certified inspector, turn to the pros at Southwest Wire Rope. Our experienced team can provide insights and recommendations for the type of wire rope, end fittings, hardware, and operational procedures that best suit your facilities and equipment. We look forward to answering your questions and forming a lasting partnership. For more information, browse our service offering and get in touch.

Wire ropes are used in many industries worldwide, whether lifting objects in the construction industry or pulling cable cars up a mountainside. Wire ropes need to be strong and reliable to accomplish heavy lifting tasks, but what is the strongest wire rope?

The strongest steel wire rope is a 2 ½ inch thick 6 x 36 IWRC (independent wire rope core) cable with a breaking strength of 291 000 Kg. Only 20% of the total breaking strength is used when lifting objects to maintain a high safety margin and prevent the cable from failing. 

Wire ropes are so much more than just a piece of wire attached to an object that needs to be lifted. If you would like to find out what makes a wire rope strong and how much it can lift, then read on:

What Is The Strongest Wire Rope?

A wire rope is known as a machine because it has many components that it relies on to give it the strength required. A wire rope consists of multiple steel wires that form individual strands laid in a spiral pattern around a core. The specific pattern that the cable is laid in will give it strength and flexibility and assist the cable in bending stress.

The strongest steel wire rope is a 2 ½ inch (64mm) 6 x 36 independent wire rope core (IWRC) with a Warrington seal. The 6 x 36 Wire rope offers the highest maximum breaking load in its class, 291 000kg.

Wire ropes are not utilized to carry or pull weight up to their maximum breaking load but rather only use 20-30% of this measure to maintain a large safety margin. Nevertheless, this is still very impressive.

A 2 ½ inch 6×36 cable can be used as individual strands and laid into a thicker wire rope to make it even stronger, but this will only be done for very limited one-off applications.

The Different Wire Rope Patterns

A strand pattern can be affected by the layers, the wires per layer, and the wire diameter. The following five patterns are the most commonly used in wire rope construction:

• The Single Layer – The most common example is a seven-wire strand with a single-wire center and six wires of the same diameter around it.
• The Filler Wire – Two layers of uniform-size wire are wrapped around a central core, with the middle layer consisting of half the amount of wires as the outer layer. The smaller filler wires are equal to the number of wires in the inner layer and are laid in the valleys between the wire.
• The Seale – Two layers of wires are wrapped around a central core with the same amount of wires in each layer, and all the wires are the same thickness. The larger outer wires rest in the gaps between the smaller inner wires.
• The Warrington – Two layers of wires are wrapped around a central core, and they are the same thickness of wire as in the inner layer. Two different wire diameters are then wrapped interchanging (large and small) to form the outer layer.
• The Combination – A combination strand is made using any combination of two or more of the patterns listed above.

The 3 Common Wire Rope Lays

The strand direction and type of lay refer to how the wires are laid to make up a strand, either right or left twist, and how the strands are laid around the core either regular lay, lang lay, or alternate lay.

• Regular Lay – wires in the strands are laid opposite in direction to the lay of the strands
• Lang Lay – wires are laid in the same direction as the lay of the strands
• Alternate Lay – The wire rope consists of alternating Regular Lay, and Lang Lay strands are mainly used for special and unique applications.

The Largest On Shore Lifter Crane

In Ingleside, Texas, a crane, known as the ‘Heavy lifting devise,’ is a 550-foot crane rated to lift 13000 metric tons in a single lift. The Crane has successfully lifted 10 000mT in a single lift and is mainly used to assemble large off-shore oil rigs. The Crane utilizes a 2 ½ inch 6 x 36 cable in an array of pulleys to achieve this massive lifting capacity.

World Record Wire Rope

Wire Rope manufacturer Redaelli achieved the Guinness World Record for the heaviest wire rope in the world in 2013. The 4003 meters (13 134ft) cable weighs 438 tons. The Wire Rope is 153mm (6.06 inches) thick and was manufactured to operate in the marine field.

 It was designed to withstand the massive crushing pressures in the ocean at depths below 3000m (9 845ft) and only has a load limit of 1000 tons. The Wire Rope will be used in the recovery operation of large vessels at the bottom of the sea.

Alternatives To Steel Wire Rope

In the heavy lifting industry, three types of rope are recognized for their superior lifting and breaking strength abilities. Each rope type is much lighter and offers smaller diameters than steel wire rope.

• Aramid rope is made from a robust fiber called Twaron; this rope has a high fiber ratio, is thermally stable, and can withstand chemical spills. Aramid rope’s advantage over steel wire rope is its smaller diameter and lighter weight.
• Dyneema rope is a Polyethylene fiber that offers maximum strength at minimum weight and is as strong as steel wire rope.
• Carbon Fibre ropes are made with Carbon T-700 and are also as strong as their steel wire counterparts. The carbon ropes offer a greatly reduced weight compared to steel and have the same breaking strengths. 

Conclusion

The Strongest wire rope is a 2 ½ inch steel cable and has a breaking strength of 291 tonnes. Many different factors make a cable strong, mainly due to the rope’s thickness and spiral pattern. Many achievements have been made in the lifting industry with new technology in developing high-strength ropes equally as strong as wire rope. But wire rope is still used for heaving lifting in many industries.

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