wire rope failure types supplier
In 1998, a crane load line broke while lifting the south topside module of the Petronius platform, dropping the module into the Gulf of Mexico. The cost was estimated to be around 116 million US dollars. Since 1999 more than 60 people have been killed as a result of wire ropes breaking and more than 65 associated injuries.
Not many people appreciate that there are literally thousands of wire rope designs, most of which can be put into a specific category. According to BS ISO 4309 2010 there are currently more than 25 categories of crane wire rope, each with differing characteristics and also different discard criteria. Deterioration can be measured, counted or calculated and the wire rope eventually taken out of service based on sophisticated discard criteria published in chosen standards, codes of practice or users handbooks.
Unfortunately there is no simple answer to either of these questions. All wire ropes will eventually break due to corrosion, wear or fatigue even if they are maintained and used properly. Unpredictable wire rope failures will inevitably occur, quite often when you least expect it if the discard criteria is ignored, or those using the equipment are ignorant of it.
James Dawes of Topeka, Illinois, was killed in 2008 after being struck by the boom of a Link-Belt crane; the accident was caused by the boom hoist wire rope breaking. The crane rope had been inspected, but a report said that the inspector failed to reject the rope showing a high number of visible wire breaks. Premature or unexpected wire rope failures can also be attributed to poor manufacture, incorrect handling and storage, poor installation technique, poor selection or fitting of its termination, infrequent or inadequate inspection and poor maintenance. Of course there is always the possibility that mechanical damage can occur and this is usually attributed to human error.
It is necessary, particularly during offshore operations that frequent inspections are carried out over the whole length of the working part of all steel wire ropes. The frequency of inspections should be based on the severity of use and risk assessment and particular attention should be paid to the critical areas of the wire rope; areas that are frequently running over sheaves, compensating sheaves and the rope termination to name a few.
If a wire rope has not been subjected to an abnormal environmental condition such as excessive heat, chemical attack or any corrosive solution and it has not been the victim of any form of mechanical damage, then trained operatives and inspectors can reasonably predict the length of time the steel wire rope is likely to last. That prediction, of course, will be dependent on the knowledge and experience of those making it coupled with known facts about the rope, its current condition and the application it is running on. The Inspector should be aware of the previous rope’s history, capacities of loads and the reeving systems employed together with the frequency of use etc.
Various standards and codes of practice have been written by recognized bodies and institutes based on the experience of experts or representatives of corporate organizations who have a vested interest. These standards do offer guidance on when a wire rope should be removed from service based on wear, abrasion and fatigue amongst others things, but none of these standards have any legal status except when they are called up by contract. Indeed they can all be supported or overturned in a court of law by an expert.
The users handbook, or more importantly the safe use instructions do have legal status. In many parts of the world these days, suppliers of cranes or any machinery for that matter, issue safe use instructions with new equipment. Modern applications employ modern wire rope and, in some cases, sheaves and pulleys that are made with materials other than steel. Original equipment manufacturers of such applications may impose discard criteria for the wire rope that is stricter than those in chosen standards. By law the user must follow manufacturers’ instructions.
Wire ropes will deteriorate much more quickly if they go dry and are allowed to remain in that condition. Tests have proven that a dry rope will lose up to 60 % of its expected life if it is not re-lubricated. There are differing schools of thought as to how wire rope should be lubricated. Some believe that a thin lubricant should be applied using a paintbrush. It is thought that this method allows the lubricant to penetrate. Experience has proven however, that thin penetrative lubricants will easily drain away or fly off in hot climates.
Another school of thought, and the one I stand on, is that grease should be pressure lubricated into the rope. This method, if applied properly, will ensure that the grease penetrates the rope pushing out the old lubricant with it and any possible corrosive agents such as salt water and sand. Any lubricant that is used must be compatible with the type that was applied previously and it is a good idea to consider the environment as well.
In any event, wire ropes usually announce that they are about to break. A series of individual wire breaks can be heard. These are likely to go on over several seconds and continuing for up to ten minutes before ultimate failure. Therefore, if operatives understand the warning signals, expensive incidents could be avoided.
Figure 2 shows two pieces of the same rope, the bottom portion quite clearly shows a progression of wire breaks. The operator was able to put the load down before disaster struck. The root cause of this fault was core deterioration brought about by internal corrosion.
To answer the other question on accountability, the list is extensive. Usually the first suspect is the wire rope manufacturer and that may be where the problem lies, but very often that is not the case. What if you were supplied the wrong rope for the application? Maybe you ordered the wrong rope or your buyer bought it from a cheap unapproved manufacturing source.
Perhaps your supplier is responsible, maybe he provided you with a rope that was produced to the wrong specifications. Would you know the difference? Perhaps you were sold a rope that had been stored in the suppliers or manufactures stock for a number of years and, whilst it was there, it hadn’t been properly maintained. Maybe the rope had been badly handled or installed incorrectly. The list of possibilities is endless.
In 1999 a ropeway in the French Alps snapped causing 21 deaths. In 2003, a ropeway wire rope snapped and 7 people died and a further 42 were injured. In 2007 a crane wire rope snapped at New Delhi’s metro, the entire structure tumbled down crushing workers underneath, six people were killed and 13 more were injured. In 2009 26 people were killed and 5 people were injured when a rope failed in a mine and a further 6 people were injured when a lift rope broke inside London’s Tower Bridge.
If you find yourself in the unfortunate situation after the unthinkable premature failure of a wire rope, then you might like to know that there are independent analytical services capable of determining probable cause. One of these is Doncaster Analytical Services Ltd (DAS), they have an independent metallurgical laboratory providing factual analysis and testing of wire rope for any reason (contact Mr Shui Lee, Technical Director, Tel +44(0)1302 556063, email: shui.lee@doncasteranalyticalservices. com).
You do not need a wire rope to fail in order to learn. Careful analysis of discarded ropes can also give you valuable information about your application, the way it operates, and the rope you have been using.
Based on this information, a trained, skilled and experienced inspector will be able to advise on a better crane or wire rope design, or to an improvement in maintenance procedures and safety.
Safety should be the top concern of anyone employed in rigging. When working a job where so many lives could be cut short due to carelessness, there is no excuse for laziness or distraction. Rigs should be inspected thoroughly for any potential areas of breakage. It is important for employees to gain a fluency in the causes of wire rope damage and failures so they can spot areas of weakness and fix them before they grow into a dangerous problem.
Corrosion issues in wire ropes are one of the most difficult causes of wire rope damage and failures to identify, which is why it is one of the most dangerous. Wire rope failures due to corrosion are typically the result of poor lubrication. You can measure some amount of the lubrication by looking at the pitted surface of every individual rope, but this tells us little of the damage done to the core. Since it is difficult to identify the full spectrum of corrosion, this break stands apart as mysterious and deadly.
Abrasion-caused failure occurs when the wire rope has been damaged by irregular contact with hoist sheaves and drums or when it awkwardly rubs against an object such as shelving or a crane girder. It is also often caused by poorly grooved drums and sheaves. You know the wire ropes have experienced abrasions when the wire ends are worn thin.
When hoist ropes go through repetitive bending over sheaves, cracks will eventually develop in the individual wires. Sections of the wire that move over the sheaves develop the worst fatigue. The damage can often be seen by the naked eye. Whenever one broken wire appears due to fatigue, more will follow. Since these issues are essentially the result of wear and tear on the rope wire, they are considered a normal part of operating a crane.
Being fluent in safety measures is just as valuable to an employer as competency with cable rigging hardware. People who know how to spot areas for potential failures can keep themselves and their coworkers secure, which saves time, money, and even lives.
Unfortunately, many phone calls into ITI Field Services begins this way, “We have had an incident with a wire rope and we believe the rope failed. How do we determine the cause of failure?”
Fortunately, the calls come in because wire rope users want to determine cause of failure in an effort to improve their crane, rigging and lifting activities.
A wire rope distributor received a hoist rope and sockets from a rubber-tired gantry. The rope and sockets were returned by the customer who believed the rope and sockets failed. The distributor hired ITI Field Services to conduct an analysis on the rope and sockets to determine the cause of the failure and to produce written documentation.
Based on the findings of the examination, fatigue-type breaks in the wires indicated that the wire rope lost significant strength due to vibration. There was no indication that the rope was overloaded. The poured sockets showed no evidence of abnormalities in the pouring method, wire zinc bonding length or the materials used in the speltering process. The conclusion of the inspection is that rope failed due to fatigue.
Wire rope examination is just one of the many services that is offered by ITI Field Services. ITI has some of the most highly-regarded subject-matter experts in the crane and rigging industry with experience in performance evaluations, litigation, accident investigations, manual development and critical lift planning reviews.
Hoisting loads with a wire rope is a simple operation. Hook it up; lift it. Turns out, it’s more complicated than it appears. The details of setting up, inspecting, and maintaining lifts with wire ropes are not complicated, but are critical. A lift that goes awry is dangerous. A bad lift puts workers at risk. In this article, we discuss the causes of wire rope failure and how to avoid them.
Abrasion breaks are caused by external factors such as coming into contact with improperly grooved sheaves and drums. Or just hitting against some object during operation. Worn, broken wire ends is the result of an abrasion break. Common causes of abrasion breaks include:
Core slippage or protrusion is caused by shock load or improper installation of the wire rope. Excessive torque can cause core slippage that forces the outer strands to shorten. The core will then protrude from the rope. Wire ropes designed to be rotation-resistant should be handled carefully so as not to disturb its lay length.
Corrosion breaks cause pitting on the individual wires that comprise the rope. This type of damage is caused by poor lubrication. However, corrosion breaks are also caused by the wire rope coming into contact with corrosive chemicals, such as acid.
There are many ways the strands of a rope can be crushed or flattened. Improper installation is a common cause. To avoid crushing, you’ll want the first layer of the wire rope to be very tight. You’ll also need to properly break-in a new wire rope. Other causes of crushing include cross winding, using a rope of the wrong diameter, or one that it too long.
Cracks to individual wires are caused by fatigue breaks. Fatigue breaks happen because the wire rope is being bent over the sheave over and over again. In time, the constant rubbing of the wire rope against the sheave or drum causes these breaks. Sheaves that are too small will accelerate fatigue breaks because they require more bending. Worn bearings and misaligned sheaves can also cause fatigue. A certain number of broken wires is acceptable. The worker responsible for equipment inspection prior to use should know the American Society of Mechanical Engineers (ASME) standard for wire ropes. The ASME standard determines whether the wire rope must be replaced. (https://www.asme.org/)
Selecting the right wire rope for the job is critical. There is never a perfect rope. For example, you will need to make a tradeoff between fatigue resistance and abrasion resistance. There are several aspects to wire rope design to consider, including:
In general, the proper wire rope will have a strength rating high enough to handle the load. (Strength is rated in tons.) It can handle the stress of repeated bending as it passes over sheaves or around drums. How you attach the rope in preparation for the lift matters and should only be handled by properly trained workers.
The wire rope (and all the equipment involved in a lift) should be fully inspected prior to the lift. The worker performing the inspection should be well-versed in the types of damage that can cause a wire rope to fail. Using a checklist is highly recommended. This will ensure that the inspection is complete. Worker and supervisor signoff will increase accountability. Of course, the wire rope must be maintained according to the manufacturer’s instructions.
How a wire rope is stored, the weather conditions in which it is used, and how they are cleaned all affect its useful life. The Occupational Safety and Health Administration (OSHA) provides these recommendations: (Source: https://www.osha.gov/dsg/guidance/slings/wire.html)
Preventing wire rope failures starts with selecting the right one for the job. When in doubt, talk with your local equipment dealer. Be prepared to discuss your specific job requirements. A thorough inspection of the wire rope prior to using it is critical. Finally, properly store your wire rope. The selection, inspection, and care of wire rope is key to job safety.
Wire rope manufacturers produce their products in order to provide a high load capacity, versatile alternative to weaker ropes like manila rope or hemp rope. Wire rope products are used for a wide variety of motion transmission applications, among them: lifting, baling, tie down, hoisting, hauling, towing, mooring, anchoring, rigging, cargo control, guidance and counterbalance. They can also be used as railing, fencing and guardrailing.
Wire rope is a must-have for many heavy duty industrial applications. From mining to forestry to marine and beyond, there’s wire rope for almost every job. Some of the many industries in which wire rope is popular include: construction, agriculture, marine, industrial manufacturing, fitness, sports and recreation (plastic coated cables for outdoor playground equipment and sports equipment), electronics, theater (black powder coated cables for stage rigging), mining, gas and oil, transportation, security, healthcare and consumer goods.
Wire rope as we know it was invented just under 200 years ago, between 1831 and 1834. At that time, the goal was to create a rope strong enough to support work in the mines of the Harz Mountains. Invented by Wilhelm Albert, a German mining engineer, this wire rope consisted on four three-stranded wires. It was much stronger than older rope varieties, such as manila rope, hemp rope and metal chain rope.
While studying at Freiburg School of Mines, a man named L.D.B. Gordon visited the mines in the Harz Mountains, where he met Albert. After he left, Gordon wrote to his friend Robert Stirling Newall, urging him to create a machine for manufacturing wire ropes. Newall, of Dundee, Scotland, did just that, designing a wire rope machine that made wire ropes with four strands, consisting of four wires each. After Gordon returned to Dundee, he and Newall, along with Charles Liddell, formed R.S. Newall and Company. In 1840, Newall received a patent for “certain improvements in wire rope and the machinery for making such rope.”
In 1841, an American manufacturer named John A. Roebling began producing wire rope for suspension bridges. Soon after, another set of Americans, Josiah White and Erskine Hazard, started incorporating wire rope into coal mining and railroad projects, forming Lehigh Coal & Navigation Company (LC&N Co.). In 1848, wire rope from their wire rope factory in Mauch Chunk, Pennsylvania provided the lift cables needed to complete the Ashley Planes Project. This project sought to improve the performance and appearance of the freight railroad that ran through Ashley, Pennsylvania, by adding lift cables. This increased tourism and increased the railroad’s coal capacity. Before, cars took almost four hours to return; after, they took less than 20 minutes.
Wire rope likewise changed the landscape (again) in Germany, in 1874, when an engineering firm called Adolf Bleichert & Co. used wire rope to build Bi-cable aerial tramways. These allowed them to mine the Ruhr Valley. Several years later, they also used wire rope to build tramways for the German Imperial Army and the Wehrmacht. These tramways were wildly successful, opening up roads in Germany and all over Europe and the USA.
Since the 1800s, manufacturers and engineers have found ways to improve wire rope, through stronger materials and material treatments, such as galvanization, and different rope configurations. Today, wire rope makes possible many heavy industrial processes. It has become a necessity of the modern world.
Strands are made by tightly twisting or braiding individual wire together. One strand could have anywhere between two and several dozen wire filaments depending on the necessary strength, flexibility, and weight capacity.
One of the most dynamic elements of wire cables is the inner core. The strands are wrapped around the core, and it can be made of different metals, fibers, or even impregnated fiber materials. For heavy applications, cores are often made of a different strand of wire called an independent wire rope core (IWRC). An IWRC has a considerable amount of flexibility and it is still very strong. In fact, at least 7.5% of the strength increase in a wire rope can be attributed to an IWRC.
While they sometimes use other metals, like aluminum, nickel, copper, titanium, and even bronze for some applications, manufacturers primarily produce wire rope from steel. This is because steel is very strong and stretchable. Among the most common types they use are: galvanized wire, bright wire, stainless steel and cold drawn steel.
Of the wire rope steels, cold drawn carbon steel wire is most popular, although stainless steel wire rope is sometimes employed as well. Stainless steel rope is most popular for its anti-corrosive properties. Bright wire rope, a type of ungalvanized steel wire rope, is also popular. For added strength and durability, galvanized steel wire rope/galvanized steel cables are a very popular choice. Galvanized aircraft cable, for example, is always a must in aerospace.
When choosing or designing a custom wire rope for your application, suppliers consider factors such as: the environment in which the rope will function, required rust resistance, required flexibility, temperature resistance, required breaking strength and wire rope diameter. To accommodate your needs, manufacturers can do special things like: make your rope rotation resistant, color code your rope, or add a corrosion resistant coating. For instance, sometimes they specially treat and coat a cable with plastic or some other compound for added protection. This is particularly important to prevent fraying if the wire rope is often in motion on a pulley.
Manufacturers and distributors identify the differences in wire cable by listing the number of strands and the amount of wires per strand so that anyone that orders understand the strength of the cable. Sometimes they are also categorized by their length or pitch. Common examples of this include: 6 x 19, 6 x 25, 19 x 7, 7 x 19, 7 x 7, 6 x 26 and 6 x 36.
More complex wire rope identification codes connote information like core type, weight limit and more. Any additional hardware like connectors, fasteners, pulleys and fittings are usually listed in the same area to show varying strengths and degrees of fray prevention.
Cable wire rope is a heavy-duty wire rope. To give it its high strength, manufacturers construct it using several individual filaments that are twisted in strands and helically wrapped around the core. A very common example of cable wire rope is steel cable.
Spiral rope is made up an assemblage of wires with round or curved strands. The assemblage features at least one outer layer cord pointed in the opposite direction of the wire. The big advantage of spiral ropes is the fact that they block moisture, water and pollutants from entering the interior of the rope.
Similarly, stranded rope steel wire is made up of an assemblage of spirally wound strands. Unlike spiral rope, though, its wire patterns have crisscrossing layers. These layers create an exceptionally strong rope. Stranded rope may have one of three core material types: wire rope, wire strand or fiber.
Wire rope chain, like all chains, is made up of a series of links. Because it is not solid, wire rope chain is quite flexible. At the same time, it is prone to mechanical failure.
Wire rope slings are made from improved plow wire steel, a strong steel wire that offers superior return loop slings and better security. The plow wire steel also shields rope at its connection points, which extends its working life. Wire rope slings, in general, provide their applications with increased safety, capacity and performance. Wire rope sling is a rope category that encompasses a wide range of sub-products, such as permaloc rope sling, permaloc bridle slings and endless slings. These and other wire rope slings may be accompanied by a wide variety of sling terminations, such as thimbles, chokers and hooks.
Wire rope offers its user many advantages. First, design of even distribution of weight among strands makes it ideal for lifting extremely heavy loads. Second, wire rope is extremely durable and, when matched properly to the application, can withstand great stress and elements like corrosion and abrasion. In addition, it is very versatile. Its many iterations and the ways in which the rope can treated means that users can get rope custom fit for virtually any application.
Depending on the type of wire rope with which you are working and your application, you may want to invest in different accessories. Among these accessories are: wire rope clips, steel carabiners, fittings, fasteners and connections.
To ensure that your wire rope quality remains high, you must regularly inspect them for wear and degradation. The right wire rope should be selected for a particular use. Watch out for performance-impacting damage like: rust, fraying and kinks. To make sure that they stay in tip-top shape, you should also clean and lubricate them as needed. Check for this need as a part of your regular inspection.
Rope care is about more than inspection. It’s also about making an effort to use and store them properly every time you use them. For example, never exceed your rope’s rated load and breaking strength. Doing so will not only cause the weakening of your cable, but it may even cause immediate breakage. In addition, always store your wire rope cable in a dry and warm area, away from those elements that could cause premature rusting or other damage. Finally, always carefully wind your wire rope when you’re done with it, so as to avoid kinks. If you follow all these tips and treat your wire rope assemblies well, they will reward you with a long and productive service life.
Always make sure that you purchase wire rope that matches your industry and regional standards. Some of the most widely referenced standards organizations for wire rope include: ISO, ASTM International and OSHA. Talk over your specifications and application with your wire rope supplier to figure out what’s best for you.
If you’re in the market for a wire rope or a wire rope assembly, the best way to know you’re getting something that will both perform well and be safe if by working with a vetted professional. Find one among the list we’ve provided on this page. Check out their profiles to get an idea of the services and products they offer. Pick out three or four to whom you’d like to speak, and reach out. Talk to them about your specifications, standard requirements and budget. Ask about lead times and delivery options. Once you’ve spoken with all of them, compare and contrast their answers. You’ll know you’ve found the one when you talk to a wire rope company that is willing to go above and beyond for your satisfaction.
A wire rope is a type of cable that includes several wire strands laced together to form a single wire. Generally, both the terms “wire” and “rope” are used interchangeably with “wire rope”; however, according to the technical definition, to be labeled a wire rope, the cable must have a thickness of at least 9.52 mm. As a versatile, high load capacity alternative to natural fiber ropes such as hemp and manila, wire rope provides motion transmission through nearly all angles, tie down, counterbalance, guidance, control, or lift.
Modern wire rope was invented by Wilhelm Albert, a German mining engineer, between 1831 and 1834. He developed them in order for work in the mines in the Harz Mountains. This rope replaced weaker natural fiber ropes, like hemp rope and manila rope, and weaker metal ropes, like chain rope.
Albert’s rope was constructed of four three-stranded wires. In 1840, a Scot named Robert Stirling Newall improved upon this model. A year later in the United States, American manufacturer John A. Roebling started producing wire rope, aimed at his vision of suspension bridges. From there, other interested Americans, such as Erskine Hazard and Josiah White, used wire rope in railroad and coal mining applications. They also applied their wire rope techniques to provide lift ropes for something called the Ashley Planes project, which allowed for better transportation and increased tourism in the area.
Approximately twenty-five years later, back in Germany in 1874, the engineering firm Adolf Bleichert & Co. was founded. They used wire rope to build bicable aerial tramways for mining the Ruhr Valley. Years later they built tramways for both the Wehrmacht and the German Imperial Army. Their wire rope systems spread all across Europe, and then migrated to the USA, concentrating at Trenton Iron Works in New Jersey.
Over the years, engineers and manufacturers have created materials of all kinds to make wire rope stronger. Such materials include stainless steel, plow steel, bright wire, galvanized steel, wire rope steel, electric wire, and more. Today, wire rope is a staple in most heavy industrial processes. Wherever heavy duty lifting is required, wire rope is there to facilitate.
Wire rope is strong, durable, and versatile. Even the heaviest industrial loads may be lifted with a well-made wire rope because the weight is distributed evenly among constituent strands.
There are three basic elements of which wire ropes are composed: wire filaments, strands, and cores. Manufacturers make wire rope by taking the filaments, twisting or braiding them together into strands, and then helically winding them around a core. Because of this multiple strand configuration, wire rope is also often referred to as stranded wire.
The first component, the filaments, are cold drawn rods of metal materials of varying, but relatively small diameter. The second component, the strands, can individually consist of as few as two or as many as several dozen filaments. The last component, the core, is the central element around which strands are wrapped; wire rope cores maintain a considerable amount of flexibility, while increasing strength by at least 7.5% over the strength of fiber core wire ropes.
The helical winding of the strands around the core is known as the lay. Ropes may be right hand lay, twisting strands clockwise, or they may be left hand lay, twisting strands counter-clockwise. In an ordinary lay, the individual strands are twisted in the opposite direction of the lay of the entire rope of strands to increase tension and to prevent the rope from coming unwound. Though this is most common Lang"s lay has both the strands and the rope twisted in the same direction while alternate lays, as the name suggests alternate between ordinary and Lang style lays. While alternative rope designs are available, the helical core design is often favored, as it allows a wire cable to hold a lot of weight while remaining ductile.
There are many design aspects that wire rope manufacturers consider when they are creating custom wire rope assemblies. These include: strand gauge (varies based on application strength, flexibility, and wear resistance requirements), wire rope fittings (for connecting other cables), lay, splices, and special coatings. Specially treated steel cable and plastic coated cables, for instance, are common to many application specific variations of wire rope such as push pull cable assemblies used in transferring motion between two points.
Suppliers typically identify wire cable by listing both the number of strands and the amount of wires per strand respectively, though stranded cable may alternatively be measured by their lay and length or pitch. For example, a door-retaining lanyard wire rope is identified by its 7 x 7 construction, and wire rope used for guying purposes is identified by its 1 x 19 construction. The most common types are 6 x 19, 6 x 25, 19 x 7, 7 x 7, 7 x 19, 6 x 26, and 6 x 36.
An ungalvanized steel wire rope variety. This uncoated wire rope can also be designed to resist spinning or rotating while holding a load; this is known as rotation resistant bright wire rope.
Also called a coiled wire rope, a coiled cable is a rope made from bundles of small metal wires, which are then twisted into a coil. Wire rope and cable can come in a huge variety of forms, but coiled cables specifically provide the benefits of easy storage and tidiness. Unlike other wire ropes, coiled cables do not require a spool for storage. Because it has been coiled, the cable will automatically retract into its spring-like shape when it is not in use, making it incredibly easy to handle.
A type of high strength rope, made of several individual filaments. These filaments are twisted into strands and helically wrapped around a core. One of the most common types of wire rope cable is steel cable.
Wire rope made not as one solid piece, but as a piece made up of a series of metal links. Wire rope chain is flexible and strong, but it is more prone to mechanical failure than wire rope.
Push pull cables and controls are a particular type of control cable designed for the positive and precise transmission of mechanical motion within a given system. Unlike their counterpart pull-pull cables, these wire rope assemblies offer multidirectional control. Additionally, their flexibility allows for easy routing, making them popular in a number of industrial and commercial applications.
Iron and steel are the two most common materials used in producing wire ropes. A steel wire is normally made from non-alloy carbon steel that offers a very high strength and can support extreme stretchable forces. For even more strength and durability, manufacturers can make stainless steel wire rope or galvanized steel wire rope. The latter two are good for applications like rigging and hoisting.
Technically, spiral ropes are curved or round strands with an assemblage of wires. This gathering of wires has at least one cord situated in the opposite direction of the wire in the outer layer of the rope. The most important trait of this rope is that all the wires included are round. The biggest benefit of this category of rope is that it does not allow the entrance of pollutants, water, or moisture.
Contain an assemblage of strands placed spirally around a core. Stranded rope steel wire patterns have different layers that cross each other to form an even stronger cable or rope. Stranded ropes contain one of three types of core: a fiber core, a wire strand core, or a wire rope core.
Provide an added level of security to a manufacturing production application. Wire rope slings are made from improved plow steel wire ropes that, apart from offering added security, also provide superior return loop slings. Plow steel wire ropes improve the life of a mechanism by shielding the rope at its connection points. The key objective of wire rope slings is to enhance the safety of an application while increasing its capacity and performance. Rope slings are also available in various sling termination options, such as hook type, chokers, and thimbles.
The eye in this rope sling is made using the Flemish Splice method. Just like a typical sling, a Permaloc rope sling improves safety and provides reverse strength meaning that the uprightness of the eye does not depend on the sleeves of the metal or alloy. Additionally, permaloc rope slings offer an abrasion resistance feature that makes them long lasting.
These slings have all the features that most other slings offer. However, compared to their counterparts, Permaloc bridle slings provide better load control, wire rope resistant crushing, robust hooks and links that work for a longer duration, and help save on maintenance requirements.
Manufacturers produce wire rope for many different reasons; from cranes to playground swings, wire ropes have something for everyone. Among the many applications of wire rope are hoisting, hauling, tie down, cargo control, baling, rigging, anchoring, mooring, and towing. They can also serve as fencing, guardrails, and cable railing, among other products.
Some of the industries that make use of wire rope include industrial manufacturing, construction, marine, gas and oil, mining, healthcare, consumer goods, and transportation. Others include the fitness industry, which uses plastic coated cable products in weight machines, the theater industry, which uses black powder coated cables for stage rigging, the recreation industry, which uses plastic coated cables for outdoor playground equipment, and the electronics industry, which uses miniature wire rope for many types of electronic equipment and communications devices.
Wire ropes are typically made from cold drawn steel wire, stainless steel wire, or galvanized wire. They may also be made from a wide variety of less popular metals, including aluminum, nickel alloy, bronze, copper, and titanium. However, nearly all wire ropes, including control cables, are made from strands of cold drawn carbon steel wires. Stainless steel rope and cables are subbed in for highly corrosive environments. Galvanized cables and galvanized wire rope are popular for their increased strength and durability; these qualities are important to specialized ropes like galvanized aircraft cable.
A core may be composed of metal, fiber or impregnated fiber materials depending on the intended application. Cores may also be another strand of wire called an independent wire rope core (IWRC).
Wire rope, depending on its application, is subject to many standard requirements. Among the most common of these are the standards detailed by OSHA, ASTM International, and ISO. Per your application and industry, you’ll likely have others you need to consider. To get a full list, talk to your service provider.
To determine the safety factor, which is a margin of security against risks, the first step involves knowing the type of load that the rope will be subjected to. The load must consider the shock loads and blowing wind effects. The safety factor is characterized in ratios; typical are 4:1 and 5:1. If a ratio is 5:1, then the tensile strength of a wire rope must be five times of the load it will be subjected to. In some applications, the ratios can go up to 10:1.
By weighing all these factors carefully, the wire rope that you will buy will be safe to use and last considerably. For the best advice and guidance, though, don’t go it alone! Find a great wire rope supplier that you can trust. You’ll know you’ve found the right supplier for you when you talk to one that can not only fulfill your requirements, but shows that they are excited to go the extra mile for you. For a company like this, browse the list near the top of the page.
As the cables play an integral role in the safety of many operations and structures, careful analysis of a wire rope and all of its capabilities and features is vital. Important qualities and physical specifications you must consider include wire rope diameter, breaking strength, resistance to corrosion, difficulty of flattening or crushing, bendability, and average lifespan.
Each of the aforementioned considerations should be compatible with the specific application for which the rope is intended as well as the environment in which such operations are undertaken. Temperature and corrosive environments often require specially coated wire ropes with increased durability.
When you use your industrial wire rope, the first thing to remember is to not exceed your rope’s rated load and breaking strength. If you do not stay within these parameters, you risk causing your rope to weaken or even break.
Rust, kinks, fraying and even carefully performed splicing will all have an impact on the performance of wire ropes. To maintain the integrity of your wire rope assembly, you need to inspect them regularly and clean and lubricate them as needed. In addition, you need to store them out of the wet and cold as much as possible. Also wrap them up properly, so they are not kinked.
A high-carbon steel having a tensile strength of approximately 260,000 psi that is roughly fifteen percent stronger than Plow Steel. Most commercial wires are made from IPS.
A low carbon steel wire of approximately 10,000 psi, which is pliable and capable of repeated stresses from bending around small sheaves. This grade is effective for tillers, guys and sash ropes.
The manner in which the wires are helically wound to form rope. Lay refers specifically to the direction of the helical path of the strands in a wire rope; for example, if the helix of the strands are like the threads of a right-hand screw, the lay is known as a right lay, or right-hand, but if the strands go to the left, it is a left lay, or left-hand.
A classification of wire rope according to its breaking strength. The rank of grades according to increasing breaking strengths is as follows: Iron, Traction, Mild Plow Steel, Plow Steel, Improved Steel, Extra Improved Steel.
The act of fastening a termination to a wire rope through physical deformation of the termination about the rope via a hydraulic press or hammering. The strength is one hundred percent of the wire rope rating.
A grade of rope material that has a tensile strength range of 180,000 to 190,000 psi. Traction steel has great resistance to bending fatigue with a minimum of abrasive force on sheaves and drums, which contributes to its long use in elevators, from which the steel gets its name.
It is composed of wire strands that are braided together. Wire braid is similar to stranded wire. The difference between the two is the fact that stranded wire features strands that are bundled together, rather than braided.
Essential parts of cable assemblies, wire rope assemblies and wire rope slings that assist spliced or swaged rope ends in connecting to other cables and keeping cables and rope from unraveling.
A wire rope cable assembly is a metallic rope consisting of bundles of twisted, spiraled, or bonded wires. While the terms wire rope and cable are often used interchangeably, cables are typically designated as smaller diameter wire ropes, specifically wire ropes with a diameter less than 3/8 inch. Therefore, wire rope cable assemblies are typically utilized for lighter duty applications.
Or cable assemblies, are cables which are composed of many spiraled bundles of wire. These cables are used to support hanging objects, connect objects, pull or lift objects, secure items, and much more.
Wire rope wholesalers can sell an extensive range of wire rope and wire rope accessories at a very affordable rate as well as in bulk. Many of the additional wire rope equipment that wire rope wholesalers provide include: swivel eye pulleys, eye nuts, eye bolts, slip hooks, spring hooks, heavy duty clips, clevis hooks, turnbuckle hooks, anchor shackle pins, s hooks, rigging blocks, and much more. Wire rope fittings will generally improve the versatility of the wire and also prevent fraying.
Mechanical properties of wire ropes, their chemical composition, and the failure analysis process for them are described. The wires are manufactured from high-carbon, plain carbon steel, with high-strength ropes most often manufactured from AISI Grade 1074. During visual failure examination, the rope, strand, and wire diameters should all be measured. Examination should also address the presence or absence of lubricant, corrosion evidence, and gross mechanical damage. Failed wires can exhibit classic cup-and-cone ductile features, flat fatigue features, and various appearances in-between. However, wires are often mechanically damaged after failure. Most nondestructive evaluation (NDE) techniques are not applicable to wire...