wire rope designation factory
Wire rope is a complex mechanical device that has many moving parts all working in tandem to help support and move an object or load. In the lifting and rigging industries, wire rope is attached to a crane or hoist and fitted with swivels, shackles or hooks to attach to a load and move it in a controlled matter. It can also be used to lift and lower elevators, or as a means of support for suspension bridges or towers.
Wire rope is a preferred lifting device for many reasons. Its unique design consists of multiple steel wires that form individual strands laid in a helical pattern around a core. This structure provides strength, flexibility, and the ability to handle bending stresses. Different configurations of the material, wire, and strand structure will provide different benefits for the specific lifting application, including:Strength
However, selecting the proper wire rope for your lifting application requires some careful thought. Our goal is to help you understand the components of a wire rope, the construction of wire rope, and the different types of wire rope and what they might be used for. This will allow you to select the best performing and longest-lasting wire rope for the job at hand.
A wire rope is, in reality, a very complicated machine. A typical 6 x 25 rope has 150 wires in its outer strands, all of which move independently and together in a very complicated pattern around the core as the rope bends. Clearances between wires and strands are balanced when a rope is designed so that proper bearing clearances will exist to permit internal movement and adjustment of wires and strands when the rope has to bend. These clearances will vary as bending occurs, but are of the same range as the clearances found in automobile engine bearings.
Understanding and accepting the “machine idea” gives a rope user a greater respect for rope, and enables them to obtain better performance and longer useful life from rope applications. Anyone who uses a rope can use it more efficiently and effectively when they fully understand the machine concept.
Wires are the smallest component of wire rope and they make up the individual strands in the rope. Wires can be made from a variety of metal materials including steel, iron, stainless steel, monel, and bronze. The wires can be manufactured in a variety of grades that relate to the strength, resistance to wear, fatigue resistance, corrosion resistance, and curve of the wire rope.
Strands of wire rope consist of two or more wires arranged and twisted in a specific arrangement. The individual strands are then laid in a helical pattern around the core of the rope.
The core of a wire rope runs through the center of the rope and supports the strands and helps to maintain their relative position under loading and bending stresses. Cores can be made from a number of different materials including natural or synthetic fibers and steel.
Lubrication is applied during the manufacturing process and penetrates all the way to the core. Wire rope lubrication has two primary benefits:Reduces friction as the individual wires and strands move over each other
The number of layers of wires, the number of wires per layer, and the size of the wires per layer all affect the strand pattern type. Wire rope can be constructed using one of the following patterns, or can be constructed using two or more of the patterns below.Single Layer – The most common example is a 7 wire strand with a single-wire center and six wires of the same diameter around it.
Filler Wire – Two layers of uniform-size wire around a center with the inner layer having half the number of wires as the outer layer. Small filler wires, equal to the number in the inner layer, are laid in valleys of the inner wire.
Seale – Two layers of wires around a center with the same number of wires in each layer. All wires in each layer are the same diameter. The large outer wires rest in the valleys between the smaller inner wires.
Warrington – Two layers of wires around a center with one diameter of wire in the inner layer, and two diameters of wire alternating large and small in the outer later. The larger outer-layer wires rest in the valleys, and the smaller ones on the crowns of the inner layer.
On a preformed wire rope, the strands and wires are formed during the manufacturing process to the helical shape that they will take in a finished wire rope.
Preformed rope can be advantageous in certain applications where it needs to spool more uniformly on a drum, needs greater flexibility, or requires more fatigue-resistance when bending.
Direction and type of lay refer to the way the wires are laid to form a strand (either right or left) and how the strands are laid around the core (regular lay, lang lay, or alternate lay).Regular Lay – The wires line up with the axis of the rope. The direction of the wire lay in the strand is opposite to the direction of the strand lay. Regular lay ropes are more resistant to crushing forces, are more naturally rotation-resistant, and also spool better in a drum than lang lay ropes.
Lang Lay– The wires form an angle with the axis of the rope. The wire lay and strand lay around the core in the same direction. Lang Lay ropes have a greater fatigue-resistance and are more resistant to abrasion.
A steel core can be an independent wire rope or an individual strand. Steel cores are best suited for applications where a fiber core may not provide adequate support, or in an operating environment where temperatures could exceed 180° F.
The classifications of wire rope provide the total number of strands, as well as a nominal or exact number of wires in each strand. These are general classifications and may or may not reflect the actual construction of the strands. However, all wire ropes of the same size and wire grade in each classification will have the SAME strength and weight ratings and usually the same pricing.
Besides the general classifications of wire rope, there are other types of wire rope that are special construction and designed for special lifting applications.
Some types of wire rope, especially lang lay wire rope, are more susceptible to rotation when under load. Rotation resistant wire rope is designed to resist twisting, spinning, or rotating and can be used in a single line or multi-part system.
Special care must be taken when handling, unreeling, and installing rotation resistant wire rope. Improper handling or spooling can introduce twist into the rope which can cause uncontrolled rotation.
Compacted strand wire rope is manufactured using strands that have been compacted, reducing the outer diameter of the entire strand, by means of passing through a die or rollers. This process occurs prior to closing of the rope.
This process flattens the surface of the outer wires in the strand, but also increases the density of the strand. This results in a smoother outer surface and increases the strength compared to comparable round wire rope (comparing same diameter and classification), while also helping to extend the surface life due to increased wear resistance.
A swaged wire rope differs from a compacted strand wire rope, in that a swaged wire rope’s diameter is compacted, or reduced, by a rotary swager machine after the wire rope has been closed. A swaged wire rope can be manufactured using round or compacted strands.
The advantages of a swaged wire rope are that they are more resistant to wear, have better crushing resistance, and high strength compared to a round strand wire rope of equal diameter and classification. However, a swaged wire rope may have less bending fatigue resistance.
A plastic coating can be applied to the exterior surface of a wire rope to provide protection against abrasion, wear, and other environmental factors that may cause corrosion. However, because you can’t see the individual strands and wires underneath the plastic coating, they can be difficult to inspect.
Plastic filled wire ropes are impregnated with a matrix of plastic where the internal spaces between the strands and wires are filled. Plastic filling helps to improve bending fatigue by reducing the wear internally and externally. Plastic filled wire ropes are used for demanding lifting applications.
This type of wire rope uses an Independent Wire Rope Core (IWRC) that is either filled with plastic or coated in plastic to reduce internal wear and increase bending fatigue life.
Remember, wire rope is a complex piece of mechanical machinery. There are a number of different specifications and properties that can affect the performance and service life of wire rope. Consider the following when specifying the best type of wire rope for your lifting application:Strength
When you select a piece of rope that is resistant to one property, you will most likely have a trade-off that affects another property. For example, a fiber core rope will be more flexible, but may have less crushing resistance. A rope with larger diameter wires will be more abrasion resistant, but will offer less fatigue resistance.
At Mazzella Companies, we offer all different kinds of wire rope from all of the leading manufacturers. We sell the highest-quality domestic and non-domestic rigging products because product quality and operating safety go hand-in-hand. We have one of the largest and most complete inventories of both domestic and non-domestic rigging and lifting products to suit your lifting needs.
If you’re looking for a standard or custom specified wire rope for your lifting project, contact a Lifting Specialist at a Mazzella Companies location near you.
We stock well over 2,000,000 feet of wire rope in our various locations … ready for immediate delivery! We provide wire rope assemblies, and manufacture bridge cables, crane cables, steel mill cables, and thousands of OEM assemblies.
Working safely with wire rope, for riggingand other purposes, requires an understanding of some of the characteristics of wire rope. Characteristics you should understand include lay, classification, and construction. We"ll explain each in this article.
The second is the relationship between the direction in which the strands are wrapped around the core and the direction that the wires within the strand are wrapped. This can be regular or lay.
And the third is the linear, or straight-line, distance a strand travels while making a single revolution around the core of the wire rope. This is known as the lay length.
The different lays and lay lengths of wire rope all have a functional purpose, and wire ropes with specific lays have different advantages and disadvantages for specific applications at work.
Another way to characterize wire rope is by the number of wires in each strand and the number of strands in the rope itself. This is known as wire rope classification.
A wire rope"s classification includes two numbers (such as 6 x 19). The first number (6, in this example) represents the exact number of strands in the rope. The second number represents the number of wires in each strand, but this number identifies a class, or range and may not be an exact number of wires.For example, a 6 x 19 class wire rope always has six strands, but may have 15-26 wires in each strand.
Hope you found this brief introduction to some aspects of wire rope, including the different parts of a wire rope and the rope"s lay, classification, and construction, helpful.
Remember there"s a lot more to learn about wire rope in order to work with it properly and safely, and thankfully, we offer two online learning courses for it--our wire rope basics online course and our wire rope safety and operations online course.
Wire rope is a complex mechanical device that has many moving parts all working in tandem to help support and move an object or load. Wire ropes are attached to a crane or hoist and are fitted with swivels, shackles or hooks. These are suitable for lifting or lowering elevators and are also used for supporting suspension bridges or towers.
In this article, we"ll cover details on the top U.S. providers of wire ropes, along with our featured list of top wire rope suppliers on Thomasnet.com.
Below is a list of featured suppliers of wire rope from our platform. Included with these companies is their location, year established and the number of employees.
Below we have assembled information on the top suppliers of wire rope in the U.S. based on currently available public sales data. The table also includes the company name, location and the number of employees.
With the help of the provided details on the wire rope suppliers in the United States in the above tables and descriptions, we hope you can use this data to further aid your sourcing decisions.
Wire rope and cable are each considered a “machine”. The configuration and method of manufacture combined with the proper selection of material when designed for a specific purpose enables a wire rope or cable to transmit forces, motion and energy in some predetermined manner and to some desired end.
Two or more wires concentrically laid around a center wire is called a strand. It may consist of one or more layers. Typically, the number of wires in a strand is 7, 19 or 37. A group of strands laid around a core would be called a cable or wire rope. In terms of product designation, 7 strands with 19 wires in each strand would be a 7×19 cable: 7 strands with 7 wires in each strand would be a 7×7 cable.
Materials 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.
Cable Construction The greater the number of wires in a strand or cable of a given diameter, the more flexibility it has. A 1×7 or a 1×19 strand, having 7 and 19 wires respectively, is used principally as a fixed member, as a straight linkage, or where flexing is minimal.
Selecting Wire Rope When selecting a wire rope to give the best service, there are four requirements which should be given consideration. A proper choice is made by correctly estimating the relative importance of these requirements and selecting a rope which has the qualities best suited to withstand the effects of continued use. The rope should possess:Strength sufficient to take care of the maximum load that may be applied, with a proper safety factor.
Strength Wire rope in service is subjected to several kinds of stresses. The stresses most frequently encountered are direct tension, stress due to acceleration, stress due to sudden or shock loads, stress due to bending, and stress resulting from several forces acting at one time. For the most part, these stresses can be converted into terms of simple tension, and a rope of approximately the correct strength can be chosen. As the strength of a wire rope is determined by its, size, grade and construction, these three factors should be considered.
Safety Factors The safety factor is the ratio of the strength of the rope to the working load. A wire rope with a strength of 10,000 pounds and a total working load of 2,000 pounds would be operating with a safety factor of five.
It is not possible to set safety factors for the various types of wire rope using equipment, as this factor can vary with conditions on individual units of equipment.
The proper safety factor depends not only on the loads applied, but also on the speed of operation, shock load applied, the type of fittings used for securing the rope ends, the acceleration and deceleration, the length of rope, the number, size and location of sheaves and drums, the factors causing abrasion and corrosion and the facilities for inspection.
Fatigue Fatigue failure of the wires in a wire rope is the result of the propagation of small cracks under repeated applications of bending loads. It occurs when ropes operate over comparatively small sheaves or drums. The repeated bending of the individual wires, as the rope bends when passing over the sheaves or drums, and the straightening of the individual wires, as the rope leaves the sheaves or drums, causing fatigue. The effect of fatigue on wires is illustrated by bending a wire repeatedly back and forth until it breaks.
The best means of preventing early fatigue of wire ropes is to use sheaves and drums of adequate size. To increase the resistance to fatigue, a rope of more flexible construction should be used, as increased flexibility is secured through the use of smaller wires.
Abrasive Wear The ability of a wire rope to withstand abrasion is determined by the size, the carbon and manganese content, the heat treatment of the outer wires and the construction of the rope. The larger outer wires of the less flexible constructions are better able to withstand abrasion than the finer outer wires of the more flexible ropes. The higher carbon and manganese content and the heat treatment used in producing wire for the stronger ropes, make the higher grade ropes better able to withstand abrasive wear than the lower grade ropes.
Effects of Bending All wire ropes, except stationary ropes used as guys or supports, are subjected to bending around sheaves or drums. The service obtained from wire ropes is, to a large extent, dependent upon the proper choice and location of the sheaves and drums about which it operates.
A wire rope may be considered a machine in which the individual elements (wires and strands) slide upon each other when the rope is bent. Therefore, as a prerequisite to the satisfactory operation of wire rope over sheaves and drums, the rope must be properly lubricated.
Loss of strength due to bending is caused by the inability of the individual strands and wires to adjust themselves to their changed position when the rope is bent. Tests made by the National Institute of Standards and Technology show that the rope strength decreases in a marked degree as the sheave diameter grows smaller with respect to the diameter of the rope. The loss of strength due to bending wire ropes over the sheaves found in common use will not exceed 6% and will usually be about 4%.
The bending of a wire rope is accompanied by readjustment in the positions of the strands and wires and results in actual bending of the wires. Repetitive flexing of the wires develops bending loads which, even though well within the elastic limit of the wires, set up points of stress concentration.
The fatigue effect of bending appears in the form of small cracks in the wires at these over-stressed foci. These cracks propagate under repeated stress cycles, until the remaining sound metal is inadequate to withstand the bending load. This results in broken wires showing no apparent contraction of cross section.
Experience has established the fact that from the service view-point, a very definite relationship exists between the size of the individual outer wires of a wire rope and the size of the sheave or drum about which it operates. Sheaves and drums smaller than 200 times the diameter of the outer wires will cause permanent set in a heavily loaded rope. Good practice requires the use of sheaves and drums with diameters 800 times the diameter of the outer wires in the rope for heavily loaded fast-moving ropes.
It is impossible to give a definite minimum size of sheave or drum about which a wire rope will operate with satisfactory results, because of the other factors affecting the useful life of the rope. If the loads are light or the speed slow, smaller sheaves and drums can be used without causing early fatigue of the wires than if the loads are heavy or the speed is fast. Reverse bends, where a rope is bent in one direction and then in the opposite direction, cause excessive fatigue and should be avoided whenever possible. When a reverse bend is necessary larger sheaves are required than would be the case if the rope were bent in one direction only.
Stretch of Wire Rope The stretch of a wire rope under load is the result of two components: the structural stretch and the elastic stretch. Structural stretch of wire rope is caused by the lengthening of the rope lay, compression of the core and adjustment of the wires and strands to the load placed upon the wire rope. The elastic stretch is caused by elongation of the wires.
The structural stretch varies with the size of core, the lengths of lays and the construction of the rope. This stretch also varies with the loads imposed and the amount of bending to which the rope is subjected. For estimating this stretch the value of one-half percent, or .005 times the length of the rope under load, gives an approximate figure. If loads are light, one-quarter percent or .0025 times the rope length may be used. With heavy loads, this stretch may approach one percent, or .01 times the rope length.
The elastic stretch of a wire rope is directly proportional to the load and the length of rope under load, and inversely proportional to the metallic area and modulus of elasticity. This applies only to loads that do not exceed the elastic limit of a wire rope. The elastic limit of stainless steel wire rope is approximately 60% of its breaking strength and for galvanized ropes it is approximately 50%.
Preformed Wire Ropes Preformed ropes differ from the standard, or non-preformed ropes, in that the individual wires in the strands and the strands in the rope are preformed, or pre-shaped to their proper shape before they are assembled in the finished rope.
This, in turn, results in preformed wire ropes having the following characteristics:They can be cut without the seizings necessary to retain the rope structure of non-preformed ropes.
They are substantially free from liveliness and twisting tendencies. This makes installation and handling easier, and lessens the likelihood of damage to the rope from kinking or fouling. Preforming permits the more general use of Lang lay and wire core constructions.
Removal of internal stresses increase resistance to fatigue from bending. This results in increased service where ability to withstand bending is the important requirement. It also permits the use of ropes with larger outer wires, when increased wear resistance is desired.
Outer wires will wear thinner before breaking, and broken wire ends will not protrude from the rope to injure worker’s hands, to nick and distort adjacent wires, or to wear sheaves and drums. Because of the fact that broken wire ends do not porcupine, they are not as noticeable as they are in non-preformed ropes. This necessitates the use of greater care when inspecting worn preformed ropes, to determine their true condition.
Lexco Cable Manufacturing is the leading manufacturer in value-added wire rope products, including wire rope, aircraft cables, and bungee cords. With products being made in Chicago, IL area and available for international shipment as well as just-in-time shipment, our in-house expertise and processes will provide you with the exact custom wire rope, cable, micro-sized cable, bungee cord, fittings, and related services to your specifications. Quantities start as low as one piece per order. Our core offering includes:
Lexco is ISO 9001:2008 certified. We successfully provide wire rope assemblies and bungee cords a wide variety of industries, including Mining, Architecture/Construction, Automotive, Military, Security, and Display/Signage.
Tyler Madison has earned its position as a leading custom manufacturer of wire rope cable assemblies through its commitment to quality and customer service. We always carry an extensive inventory of stock components to meet our customers’ simpler needs. But with an extensive background in wire rope design, we welcome the opportunity to design, engineer, and manufacture wire rope solutions to perfectly match our customers’ more specific applications. Our many industrial OEM and commercial customers have learned to expect the very best with on time deliveries and the highest quality wire rope.
Our ability to design and manufacture custom wire rope products allows us to serve a wide variety of industries. We serve the aircraft, automotive, electronics, and security industries as well as many others. Among our most popular products are our wire rope lanyards and our wire rope cable assemblies. Both these wire rope products can be manufactured with galvanized steel or stainless steel and are offered with a variety of coating options. Wire rope lanyards are commonly utilized for security, hanging, anchoring, and pulling applications, while our wire rope cable assemblies are for more heavy-duty applications. A variety of aircraft grade cables are also available including military specifications-cable.
In stricter senses, the term wire rope refers to a diameter larger than 9.5 mm (3⁄8 in), with smaller gauges designated cable or cords.wrought iron wires were used, but today steel is the main material used for wire ropes.
Historically, wire rope evolved from wrought iron chains, which had a record of mechanical failure. While flaws in chain links or solid steel bars can lead to catastrophic failure, flaws in the wires making up a steel cable are less critical as the other wires easily take up the load. While friction between the individual wires and strands causes wear over the life of the rope, it also helps to compensate for minor failures in the short run.
Wire ropes were developed starting with mining hoist applications in the 1830s. Wire ropes are used dynamically for lifting and hoisting in cranes and elevators, and for transmission of mechanical power. Wire rope is also used to transmit force in mechanisms, such as a Bowden cable or the control surfaces of an airplane connected to levers and pedals in the cockpit. Only aircraft cables have WSC (wire strand core). Also, aircraft cables are available in smaller diameters than wire rope. For example, aircraft cables are available in 1.2 mm (3⁄64 in) diameter while most wire ropes begin at a 6.4 mm (1⁄4 in) diameter.suspension bridges or as guy wires to support towers. An aerial tramway relies on wire rope to support and move cargo overhead.
Modern wire rope was invented by the German mining engineer Wilhelm Albert in the years between 1831 and 1834 for use in mining in the Harz Mountains in Clausthal, Lower Saxony, Germany.chains, such as had been used before.
Wilhelm Albert"s first ropes consisted of three strands consisting of four wires each. In 1840, Scotsman Robert Stirling Newall improved the process further.John A. Roebling, starting in 1841suspension bridge building. Roebling introduced a number of innovations in the design, materials and manufacture of wire rope. Ever with an ear to technology developments in mining and railroading, Josiah White and Erskine Hazard, principal ownersLehigh Coal & Navigation Company (LC&N Co.) — as they had with the first blast furnaces in the Lehigh Valley — built a Wire Rope factory in Mauch Chunk,Pennsylvania in 1848, which provided lift cables for the Ashley Planes project, then the back track planes of the Summit Hill & Mauch Chunk Railroad, improving its attractiveness as a premier tourism destination, and vastly improving the throughput of the coal capacity since return of cars dropped from nearly four hours to less than 20 minutes. The decades were witness to a burgeoning increase in deep shaft mining in both Europe and North America as surface mineral deposits were exhausted and miners had to chase layers along inclined layers. The era was early in railroad development and steam engines lacked sufficient tractive effort to climb steep slopes, so incline plane railways were common. This pushed development of cable hoists rapidly in the United States as surface deposits in the Anthracite Coal Region north and south dove deeper every year, and even the rich deposits in the Panther Creek Valley required LC&N Co. to drive their first shafts into lower slopes beginning Lansford and its Schuylkill County twin-town Coaldale.
The German engineering firm of Adolf Bleichert & Co. was founded in 1874 and began to build bicable aerial tramways for mining in the Ruhr Valley. With important patents, and dozens of working systems in Europe, Bleichert dominated the global industry, later licensing its designs and manufacturing techniques to Trenton Iron Works, New Jersey, USA which built systems across America. Adolf Bleichert & Co. went on to build hundreds of aerial tramways around the world: from Alaska to Argentina, Australia and Spitsbergen. The Bleichert company also built hundreds of aerial tramways for both the Imperial German Army and the Wehrmacht.
In the last half of the 19th century, wire rope systems were used as a means of transmitting mechanical powercable cars. Wire rope systems cost one-tenth as much and had lower friction losses than line shafts. Because of these advantages, wire rope systems were used to transmit power for a distance of a few miles or kilometers.
Steel wires for wire ropes are normally made of non-alloy carbon steel with a carbon content of 0.4 to 0.95%. The very high strength of the rope wires enables wire ropes to support large tensile forces and to run over sheaves with relatively small diameters.
In the mostly used parallel lay strands, the lay length of all the wire layers is equal and the wires of any two superimposed layers are parallel, resulting in linear contact. The wire of the outer layer is supported by two wires of the inner layer. These wires are neighbors along the whole length of the strand. Parallel lay strands are made in one operation. The endurance of wire ropes with this kind of strand is always much greater than of those (seldom used) with cross lay strands. Parallel lay strands with two wire layers have the construction Filler, Seale or Warrington.
In principle, spiral ropes are round strands as they have an assembly of layers of wires laid helically over a centre with at least one layer of wires being laid in the opposite direction to that of the outer layer. Spiral ropes can be dimensioned in such a way that they are non-rotating which means that under tension the rope torque is nearly zero. The open spiral rope consists only of round wires. The half-locked coil rope and the full-locked coil rope always have a centre made of round wires. The locked coil ropes have one or more outer layers of profile wires. They have the advantage that their construction prevents the penetration of dirt and water to a greater extent and it also protects them from loss of lubricant. In addition, they have one further very important advantage as the ends of a broken outer wire cannot leave the rope if it has the proper dimensions.
Stranded ropes are an assembly of several strands laid helically in one or more layers around a core. This core can be one of three types. The first is a fiber core, made up of synthetic material or natural fibers like sisal. Synthetic fibers are stronger and more uniform but cannot absorb much lubricant. Natural fibers can absorb up to 15% of their weight in lubricant and so protect the inner wires much better from corrosion than synthetic fibers do. Fiber cores are the most flexible and elastic, but have the downside of getting crushed easily. The second type, wire strand core, is made up of one additional strand of wire, and is typically used for suspension. The third type is independent wire rope core (IWRC), which is the most durable in all types of environments.ordinary lay rope if the lay direction of the wires in the outer strands is in the opposite direction to the lay of the outer strands themselves. If both the wires in the outer strands and the outer strands themselves have the same lay direction, the rope is called a lang lay rope (from Dutch langslag contrary to kruisslag,Regular lay means the individual wires were wrapped around the centers in one direction and the strands were wrapped around the core in the opposite direction.
Multi-strand ropes are all more or less resistant to rotation and have at least two layers of strands laid helically around a centre. The direction of the outer strands is opposite to that of the underlying strand layers. Ropes with three strand layers can be nearly non-rotating. Ropes with two strand layers are mostly only low-rotating.
Stationary ropes, stay ropes (spiral ropes, mostly full-locked) have to carry tensile forces and are therefore mainly loaded by static and fluctuating tensile stresses. Ropes used for suspension are often called cables.
Track ropes (full locked ropes) have to act as rails for the rollers of cabins or other loads in aerial ropeways and cable cranes. In contrast to running ropes, track ropes do not take on the curvature of the rollers. Under the roller force, a so-called free bending radius of the rope occurs. This radius increases (and the bending stresses decrease) with the tensile force and decreases with the roller force.
Wire rope slings (stranded ropes) are used to harness various kinds of goods. These slings are stressed by the tensile forces but first of all by bending stresses when bent over the more or less sharp edges of the goods.
Technical regulations apply to the design of rope drives for cranes, elevators, rope ways and mining installations. Factors that are considered in design include:
Donandt force (yielding tensile force for a given bending diameter ratio D/d) - strict limit. The nominal rope tensile force S must be smaller than the Donandt force SD1.
The wire ropes are stressed by fluctuating forces, by wear, by corrosion and in seldom cases by extreme forces. The rope life is finite and the safety is only ensured by inspection for the detection of wire breaks on a reference rope length, of cross-section loss, as well as other failures so that the wire rope can be replaced before a dangerous situation occurs. Installations should be designed to facilitate the inspection of the wire ropes.
Lifting installations for passenger transportation require that a combination of several methods should be used to prevent a car from plunging downwards. Elevators must have redundant bearing ropes and a safety gear. Ropeways and mine hoistings must be permanently supervised by a responsible manager and the rope must be inspected by a magnetic method capable of detecting inner wire breaks.
The end of a wire rope tends to fray readily, and cannot be easily connected to plant and equipment. There are different ways of securing the ends of wire ropes to prevent fraying. The common and useful type of end fitting for a wire rope is to turn the end back to form a loop. The loose end is then fixed back on the wire rope. Termination efficiencies vary from about 70% for a Flemish eye alone; to nearly 90% for a Flemish eye and splice; to 100% for potted ends and swagings.
When the wire rope is terminated with a loop, there is a risk that it will bend too tightly, especially when the loop is connected to a device that concentrates the load on a relatively small area. A thimble can be installed inside the loop to preserve the natural shape of the loop, and protect the cable from pinching and abrading on the inside of the loop. The use of thimbles in loops is industry best practice. The thimble prevents the load from coming into direct contact with the wires.
A wire rope clip, sometimes called a clamp, is used to fix the loose end of the loop back to the wire rope. It usually consists of a U-bolt, a forged saddle, and two nuts. The two layers of wire rope are placed in the U-bolt. The saddle is then fitted to the bolt over the ropes (the saddle includes two holes to fit to the U-bolt). The nuts secure the arrangement in place. Two or more clips are usually used to terminate a wire rope depending on the diameter. As many as eight may be needed for a 2 in (50.8 mm) diameter rope.
The mnemonic "never saddle a dead horse" means that when installing clips, the saddle portion of the assembly is placed on the load-bearing or "live" side, not on the non-load-bearing or "dead" side of the cable. This is to protect the live or stress-bearing end of the rope against crushing and abuse. The flat bearing seat and extended prongs of the body are designed to protect the rope and are always placed against the live end.
An eye splice may be used to terminate the loose end of a wire rope when forming a loop. The strands of the end of a wire rope are unwound a certain distance, then bent around so that the end of the unwrapped length forms an eye. The unwrapped strands are then plaited back into the wire rope, forming the loop, or an eye, called an eye splice.
A Flemish eye, or Dutch Splice, involves unwrapping three strands (the strands need to be next to each other, not alternates) of the wire and keeping them off to one side. The remaining strands are bent around, until the end of the wire meets the "V" where the unwrapping finished, to form the eye. The strands kept to one side are now re-wrapped by wrapping from the end of the wire back to the "V" of the eye. These strands are effectively rewrapped along the wire in the opposite direction to their original lay. When this type of rope splice is used specifically on wire rope, it is called a "Molly Hogan", and, by some, a "Dutch" eye instead of a "Flemish" eye.
Swaging is a method of wire rope termination that refers to the installation technique. The purpose of swaging wire rope fittings is to connect two wire rope ends together, or to otherwise terminate one end of wire rope to something else. A mechanical or hydraulic swager is used to compress and deform the fitting, creating a permanent connection. Threaded studs, ferrules, sockets, and sleeves are examples of different swaged terminations.
A wedge socket termination is useful when the fitting needs to be replaced frequently. For example, if the end of a wire rope is in a high-wear region, the rope may be periodically trimmed, requiring the termination hardware to be removed and reapplied. An example of this is on the ends of the drag ropes on a dragline. The end loop of the wire rope enters a tapered opening in the socket, wrapped around a separate component called the wedge. The arrangement is knocked in place, and load gradually eased onto the rope. As the load increases on the wire rope, the wedge become more secure, gripping the rope tighter.
Poured sockets are used to make a high strength, permanent termination; they are created by inserting the wire rope into the narrow end of a conical cavity which is oriented in-line with the intended direction of strain. The individual wires are splayed out inside the cone or "capel", and the cone is then filled with molten lead-antimony-tin (Pb80Sb15Sn5) solder or "white metal capping",zincpolyester resin compound.
Donald Sayenga. "Modern History of Wire Rope". History of the Atlantic Cable & Submarine Telegraphy (atlantic-cable.com). Archived from the original on 3 February 2014. Retrieved 9 April 2014.
Wire ropes are several strands of metal wire that are twisted into a helix to form a composite rope, known as a laid rope. Large diameter wire rope consists of several strands of rope laid in what is known as cabling. Wire ropes are complex mechanical devices consisting of several moving parts that work together to help support & move an object or load.
In the lifting & rigging industries, wire rope is attached to a crane or hoist & fitted with a swivel, shackle, or hook to attach to a load and move it into a controlled case. It can also be used for lifting and lowering elevators or as a means of support for suspension bridges or towers. Wire rope is a preferred lifting tool for many reasons.
Its unique design consists of several steel wires that form separate strands placed in a helical pattern around a core. These structures provide strength, flexibility, & the ability to handle bending stresses. In the strictest sense, the term wire rope refers to a diameter larger than 3/8 inch (9.52 mm), with a smaller gauge specified cable or cord.
Initially, iron wires were used, but today the main material used for wire ropes is steel. Wire rope is made from cold-drawn wires to increase strength & durability. It may be noted that as its size decreases, the strength of the wire ropes increases.
The various materials used for wire ropes are iron, cast steel, extra strong cast steel, steel, and alloy steel, in order of increasing strength. For some purposes, wire rope can also be made from copper, bronze, aluminum alloys, and stainless steel. Wire ropes were developed in the 1830s with mining hoist applications.
Wire ropes are used in cranes and elevators for dynamic lifting and lifting and for transmission of mechanical power. It is also used to transmit forces to mechanisms, such as Bowden cables or the control surface of an airplane connected to levers and pedals in the cockpit.
Wire rope is made of threads of metal wire that are braided together to form a helix. Due to its heavy, flexible and tough characteristics, as well as being weather- and corrosion-resistant, it is commonly used in the building and construction, engineering, agriculture, aircraft, and marine industries.
Each wire strand bringing equal pressure to the bundle contributes to its strength and flexibility, making it an ideal material for pulleys. In Australia, wire rope was made of iron; Today, the materials used are mainly steel. Different industries use different types of wire ropes.
This is because the suitability of a specific wire rope for an application depends on the design, size, type of braids, and other characteristics. For example, marine-grade 316 wire rope is suitable for a variety of marine applications and settings.
Stainless steel is the standard alloy used in rope and cable. Its resistance to corrosions is much higher than that of galvanized & coated ropes, although there are no differences in strength. Therefore, it is the preferred material uses in marines and water-based salt industries.
It does not readily react to chemicals from food processing, textiles, and photographic settings. Its high resistance to corrosion, heat & cold, and pulp & paper chemicals makes stainless steel wire rope a much-needed material for manufacturing precision instruments, automobiles, fishing vessels, petrochemical equipment, & other fields.
Galvanized wire ropes are also steel wire materials that have undergone a galvanizing process to increase their corrosion resistance. The finished wire is immersed in a zinc bath to coat the product completely, i.e., it is galvanized.
Zinc is used in this process because cathode protection increases the life expectancy of the wire. Although the coating will degrade over time, it is still resistant to rust, corrosion, and other harsh chemicals. Galvanized wire can be found in the industrial and construction sectors as well as in agricultural and DIY projects.
Stainless steel and galvanized wire can be PVC coated with poly-vinyl-chloride or vinyl. Coated wire rope comes in various colors such as clear, black, white, or any other color that is required in various industries. PVC coated wire is flexible, weather-resistant, and very cost-effective.
Nylon-coated wire, although not as flexible as PVC, is abrasion-resistant and ideal for businesses in extremely cold regions. Wire ropes can be assembled to suit specific applications. If you have a project requiring a specific type of wire rope, send us an inquiry, and we’ll send you a special quote.
The wire is the smallest component of wire rope, and they form the individual strands in the rope. Wire can be made from a variety of metal materials, including steel, iron, stainless steel, Monel, and bronze. Wires can be manufactured in varieties of grades that are related to wire rope strength, wear resistance, fatigue resistance, corrosion resistance, and curve.
These strings symbolize the smallest component of a wire rope and are tied together around a core to form complete wire ropes. The wire themselves can be coated but are usually available in “bright” or uncoated finishes.
Wire rope strings form two or more wires wrapped around an axial member in a geometric pattern or in combination with steel wires and other materials. These individual strands are then placed around the core in a helical pattern. Strands represent the major part that serves as the primary load-bearing unit.
A typical strand can form any number of strands, and the same goes for a rope that can have an ‘n’ number of strands. Wires made from larger diameter wires are more resistant to abrasion, while wires made of smaller diameter wires are more flexible.
The core of a wire rope runs through the center of the rope & supports the wires and helps them maintain their relative position under loading and bending stress. Cores can be made from many different materials, including natural or synthetic fibers and steel. It supports the strands and helps maintain their relative position under loading and bending stress.
Wire ropes are made from the various grades of steel wires with tensile strengths ranging from 1200 to 2400 MPa. The wires are first given special heat treatment & then cold drawn for the high strength and durability of the rope. Steel wire ropes are manufactured by special machines.
First, strands of wire such as 7, 19, or 37 are routed into a single strand, and then several strands, usually 6 or 8, are twisted around the core or center to form a rope. The core may be made of loops of hemp, jute, mica, or soft steel wire.
The core must be continuously saturated with lubricants for the long lives of the core as well as the entire rope. Asbestos or soft wire core is used when a rope is subjected to radiant heat, such as cranes working near furnaces.
However, a wire core reduces the rope’s flexibility, and such ropes are only used where they are subject to high compression, as in the case of multiple layers being injured on a rope drum.
The number of layers of wires, the numbers of wires per layer, & the size of the wire per layer all affect the strand pattern type. Wire ropes can be constructed using any one of the following patterns or can be made using two or more of the pattern below.
The Two-layer of similarly sized wire around a center whose inner layer is half the number of wires as the outer layer. Small fillers wires, equal to the numbers in the inner layer, are placed in the valleys of the inner wire.
Two layers of wires around centers with the same numbers of wires in each layer. All wire in each layer is of the same diameter. The larger outer strings rest in the valleys between the smaller inner strings.
The inner layer consists of two layers of wires around a center with one diameter of the wire, and the latter alternates two diameters of the larger and smaller wire in the outer. The larger wires in the outer layer are placed in the valleys & the smaller ones on the crowns of the inner layer.
On a prefabricated wire rope, the wire and wire are formed during the manufacturing process into the helical shape that they will take into a finished wire rope. Prefabricated rope can be beneficial in some applications where it needs to be spooled more evenly over the drum, more flexibility is required, or greater fatigue resistance is required when bending.
Direction and laying type refer to how the wires are laid to form a strand, either right or left & how the strands are laid around the regular core lay, lang lay, or alternate lay.
The wires are lined up with the axis of the rope. The direction of the wire held in the strand is opposite to the direction in the strand lay. Regular lat ropes are more resistant to crushing forces, are more naturally rotation-resistant, and also have a better spool in the drum than lang lat ropes.
The wires make an angle with the axis of the rope. The wire lay down, and the strand lay around the core in the same direction. Lang le ropes have greater fatigue resistance and are more resistant to abrasion.
A fiber core may be made of natural or synthetic polypropylene fibers. Fiber cores offer greater elasticity than steel cores but are more susceptible to crushing and are not recommended for high heat environments. A steel core can be independent wire ropes or an individual strand.
Steel cores are bests suited for applications where the fiber core cannot provide adequate support or in an operating environment where temperatures may exceed 180 degrees Fahrenheit. Based on what we have learned above, this wire rope description will provide the following information to the user:
Wire rope classifications provide the total number of wires in each strand, as well as the nominal or an exact number of wires. These are general classifications & may or may not reflect the actual constructions of the strands. However, all wires rope of the same size & wires grade in each classification will have similar strength and weight ratings and generally similar pricing.
Some types of wire rope, particularly lang le wire rope, are more susceptible to rotation under load. Rotation-resistant wire rope is designed to resist twisting, spinning, or twisting and can be used in a single-line or multi-part system. Special care should be taken when handling, unrolling, and installing rotation-resistant wire rope. Improper handling or spooling can introduce a twist in the rope, which can lead to uncontrolled twisting.
Compact Strand Wire Rope is manufactured using strands that have been compacted, by means of passing through a die or rollers, reducing the outside diameter of the entire strand. This process occurs before the rope is closed. This process flattens the surfaces of the outer strands in the strand but also increases the density of the strand.
This resulted in a smoother outer surface and increased strength compared to comparable round wire rope compare similar diameters and assortments while also helping to increase surface life due to increased wear resistance.
A swaged wires rope differs from a compacted strand wires rope in that the diameter of a swaged wire rope is compacted or reduced by a rotary swagger machine after the wire rope is closed. A curved wire rope can be manufactured using rounded or narrower wires.
The advantages of a swaged wires rope are that they are more resistant to wear, has better crushing resistance, and has higher strength than a round strand wire rope of similar diameter and assortment. However, a swaged wire rope may have low bending fatigue resistance.
The plastic coating may be applied to the outer surface of a wire rope to provide protection from abrasion, wear, and other environmental factors that can cause corrosion. However, because you can’t see the individuals strand & wires beneath the plastic coating, they can be difficult to inspect.
Plastic-filled wire ropes are fitted with a plastic matrix where the wires and the internal spaces between the wires are filled. Plastic fillings help improve bending fatigue by reducing wear internally and externally. Plastics-filled wire rope is used for demanding lifting applications.
This type of wires rope uses an independent wires rope core (IWRC) that is either filled with plastics or coated in plastic to reduce internal wear & increase bending fatigue life.
Strands of wire rope consist of two or more wires arranged and twisted in a specific arrangement. The individual strands are then laid in a helical pattern around the core of the rope. Strands made of larger diameter wires are more resistant to abrasion, while strands made of smaller diameter wires are more flexible.
The Three Basic Wire Rope Components · Fiber Core (F.C.), usually polypropylene, sometimes hemp (H.C.) and sisal, Independent Wire Rope Core (IWRC), Wire Strand Core (WSC)
The term cable is often used interchangeably with wire rope. However, in general, wire rope refers to diameters larger than 3/8 inch. Sizes smaller than this are designated as cables or cords. Two or more wires concentrically laid around a center wire are called a strand.
The term cable is often used interchangeably with wire rope. However, in general, wire rope refers to diameters larger than 3/8 inch. Sizes smaller than this are designated as cables or cords. Two or more wires concentrically laid around a center wire are called a strand.
A fiber core can be made of natural or synthetic polypropylene fibers. Fiber cores offer greater elasticity than a steel core but are more susceptible to crushing and not recommended for high heat environments. A steel core can be an independent wire rope or an individual strand.
Rotation-resistant wire rope refers to a series of steel ropes that minimizes the tendency to spin or rotate under load. These wire ropes boast a special design – the outer layer is twisted in the reverse direction of the inner layers for counteracting torsional forces generated from multi-layers of strands.
The helix or spiral of the wires and strands in a rope is called the lay. Regular lay denotes rope in which the wires are twisted in one direction and the strands in the opposite direction from the rope. The wires appear to run roughly parallel to the center line of the rope.
Here you will find everything you need to know about ropes and cables. What is the difference between a wire, strand and a rope? Which rope constructions do exist? What is meant by lay directions? What is the effect of stretching? What materials are available? What is a coated rope and what is it required for? These and other questions we, from Carl Stahl Technocables would like to answer here.
Strands are made of single high tensile wires. These are placed helically around an insert * (heart wire) in the steel cable factory. This is the basic model for the further rope prodution.
The lay direction indicates the direction in which the outer wires (outer strands) of the strand (cable) are laid around the center wire (core strand).
Carl Stahl Technocables uses polyamide as the standard coating material. Polyamide is an optimum cable coating, distinguished by its high wear resistance and high bending cycle capability. A further advantage of the coated cables: The coating protects the rope from dirt.
Furthermore, the coating keeps the manufacturing lubricant within the rope. This film of oil functions as a lubricant between the individual wires and strands, thereby reducing wear on the cable.
Are high temperatures or good sliding properties required of your steel wire rope? Then we use special materials for coating of the steel wire rope. For example, we recommend FEP/PTFE for temperatures of between -190°C and + 205° C.
We can also offer PA6. PA6 is stiffer than PA12 and is therefore not suitable for pulleys. However, PA6 has better sliding properties and is therefore highly suitable as a guide cable for example.
Depending on the application, the appropriate coating material is used. Don’t you know which wire rope coating is the right for your rope application? - We"re glad to help you finding the right material. Contact us directly
After the manufacturing process of the ropes and strands, small gaps remain between each wire within the strand and between each strand in the rope. When the rope is tensioned, the wires and the strand move closer to each other, and reach their optimum position. A result of this process is, that the rope elongates to a certain extent. This constructional elongation is not the same in every rope construction. It depends on lay, lay length, rope construction and other factors.
This elongation concerns the material that the single wires are made of. It occurs, when the wire is tensioned. The material elongation is proportional to the applied load. Under normal circumstances the rope will almost regain its original length as soon as the load is removed.
The diverse properties and possibilities of wire ropes and strands are attracting more and more attention when it comes to implementing mechanical applications flexibly and safely. The result is high-quality solutions for a wide range of applications, in a wide variety of industries. The possible applications of wire ropes are almost endless. Wire ropes with larger diameters up to 8.00 mm are used in mechanical engineering or in the sun protection sector. Fine wire ropes with smaller diameters from 0.09 mm are used in the medical, furniture or lighting industries, among others. Optical aspects also often play a role.
The selection of the right wire rope for the respective application is of great importance. This is done according to various criteria, which are selected on the basis of the respectivearea of application. Properties and conditions such as tensile strength, environment, corrosion resistance, form, function, surface and structureare taken into account.
Standard wire ropes and strands are made of galvanized steel, or stainless steel. Stainless steel ropes, for example, offer very high corrosion protection, are solidand have a very long service life. Wire ropes made of galvanized wire, are in many cases the most economical option and offer sufficient corrosion protection for various applications.
Carl Stahl Technocables GmbH is your competent partner from the initial consultation, through the development of technical specifications, to the manufacture of assembled ropes, Bowden cables, wire ropes and strands. We supply our products to a wide variety of industries and markets worldwide.
Ropes made of stainless steel are rustproof. They score high on durabilitydue to low abrasion, are solidand have low ductility. Stainless steel ropes offer high tensile strength for mechanical applications and are temperature resistant.
Stainless steel wire rope is the right choice for applications where the rope needs to be protected from corrosion. Applications that are likely to be used outdoors, underwater or in an area where the wire rope would be exposed to the elements. In particular, it is highly resistant to corrosion by acids and bases.
The low cost-to-benefit ratio of galvanized steel wire rope makes this the preferred material for many mechanical applications intended for indoor use such as hanging heavy signage or suspending, lifting or balancing large objects.
The standard wires for steel wire strands and cables are made of galvanised steel or stainless steel 1.4401/ AISI 316. Galvanised wire offers sufficient corrosion protection for many areas of use. If the steel wire cables and strands are to be used in highly corrosive media, we recommend stainless steels.
Performance Wire Rope Manufacturing “PWRMFG” is a Domestic Specialty Wire Stranding Company located in Houston, Texas. PWRMFG is a division of Power Manufacturing, LLC a State of Florida Limited Liability Corporation doing business as a registered company in the State of Texas. PWRMFG manufactures Specialty Strand and Wire Rope Products in both Ferrous & Non-Ferrous Alloys.
Finished Goods Certification Upon request, PWRMFG can meet any Domestic Manufacturer requirement with respect to raw materials and finished products. All Documentation of Origin for Rod, Wire, Wire Processing and Stranding are available.
Wire ropes can be seen everywhere around us, they are made of strands or bundles of individual wires constructed around an independent core, suitable for construction, industrial, fitness, commercial, architectural, agricultural, and marine rigging applications.
Wire rod is made from high carbon steel wires(0.35 to 0.85 percent carbon) in a hot rolling process of a required diameter, usually from 5.5mm to 8 mm.
Wire rod is drawn to the required diameter by the 1st drawing machine after descaling dust and rust, adding mechanical properties suitable for application.
Positioning the wires different or the same size lay in multiple layers and same direction, or cross lay and diameter is maintained by one-third of the rope size.
So in theory, it is very simple to manufacture wire ropes. However there are many more details that must be closely monitored and controlled, and this requires time and experienced personnel since it is a super complicated project you cannot imagine.
Wire rope is technically defined as multi-wire strands laid geometrically around a core while also used more generally as a term to classify multiple product families including aircraft cable, coated aircraft cable, general purpose wire rope, strand, rotation resistant wire rope, compacted/swaged wire rope, and cable laid wire rope.
Aircraft cable does not fit the definition of wire rope in the strictest sense as it does not have an independent core, but rather a strand core, in which the center is one of the strands that is laid with the outside strand layers. Aircraft cable is available in diameters 3/8" or less with breaking strengths similar to that of equal diameter independent wire rope core (IWRC) and is available in stainless steel and galvanized steel.
Wire rope can be galvanized via three processes. Listed from least corrosion-resistant to the most corrosion-resistant, they are electro-galvanizing, hot-dip galvanizing, and drawn-galvanizing. In addition to being the most corrosion-resistant types of galvanized wire rope, drawn-galvanized has another added benefit which is a breaking strength that is the same as bright wire rope does. Electro-galvanized and hot-d