what is the safety factor of wire rope sling quotation

Account should be taken of the maximum temperature that can be reached by the wire rope sling in service. This is difficult in practice but underestimation of the temperature should be avoided.

The table below summarises the necessary de-rated working load limits of a sling due to temperature, taking into account the type of rope termination, the ferrule material and the core of the rope.

Wire ropes are essential for safety purposes on construction sites and industrial workplaces. They are used to secure and transport extremely heavy pieces of equipment – so they must be strong enough to withstand substantial loads. This is why the wire rope safety factor is crucial.

You may have heard that it is always recommended to use wire ropes or slings with a higher breaking strength than the actual load. For instance, say that you need to move 50,000 lbs. with an overhead crane. You should generally use equipment with a working load limit that is rated for weight at least five times higher – or 250,000 lbs. in this case.

This recommendation is all thanks to the wire rope safety factor. This calculation is designed to help you determine important numbers, such as the minimum breaking strength and the working load limit of a wire rope.

The safety factor is a measurement of how strong of a force a wire rope can withstand before it breaks. It is commonly stated as a ratio, such as 5:1. This means that the wire rope can hold five times their Safe Work Load (SWL) before it will break.

So, if a 5:1 wire rope’s SWL is 10,000 lbs., the safety factor is 50,000 lbs. However, you would never want to place a load near 50,000 lbs. for wire rope safety reasons.

The safety factor rating of a wire rope is the calculation of the Minimum Break Strength (MBS) or the Minimum Breaking Load (MBL) compared to the highest absolute maximum load limit. It is crucial to use a wire rope with a high ratio to account for factors that could influence the weight of the load.

The Safe Working Load (SWL) is a measurement that is required by law to be clearly marked on all lifting devices – including hoists, lifting machines, and tackles. However, this is not visibly listed on wire ropes, so it is important to understand what this term means and how to calculate it.

The safe working load will change depending on the diameter of the wire rope and its weight per foot. Of course, the smaller the wire rope is, the lower its SWL will be. The SWL also changes depending on the safety factor ratio.

The margin of safety for wire ropes accounts for any unexpected extra loads to ensure the utmost safety for everyone involved. Every year there aredue to overhead crane accidents. Many of these deaths occur when a heavy load is dropped because the weight load limit was not properly calculated and the wire rope broke or slipped.

The margin of safety is a hazard control calculation that essentially accounts for worst-case scenarios. For instance, what if a strong gust of wind were to blow while a crane was lifting a load? Or what if the brakes slipped and the load dropped several feet unexpectedly? This is certainly a wire rope safety factor that must be considered.

Themargin of safety(also referred to as the factor of safety) measures the ultimate load or stress divided by theallowablestress. This helps to account for the applied tensile forces and stress thatcouldbe applied to the rope, causing it to inch closer to the breaking strength limit.

A proof test must be conducted on a wire rope or any other piece of rigging equipment before it is used for the first time.that a sample of a wire rope must be tested to ensure that it can safely hold one-fifth of the breaking load limit. The proof test ensures that the wire rope is not defective and can withstand the minimum weight load limit.

First, the wire rope and other lifting accessories (such as hooks or slings) are set up as needed for the particular task. Then weight or force is slowly added until it reaches the maximum allowable working load limit.

Some wire rope distributors will conduct proof loading tests before you purchase them. Be sure to investigate the criteria of these tests before purchasing, as some testing factors may need to be changed depending on your requirements.

When purchasing wire ropes for overhead lifting or other heavy-duty applications, understanding the safety dynamics and limits is critical. These terms can get confusing, but all of thesefactors serve an important purpose.

Our company has served as a wire rope distributor and industrial hardware supplier for many years. We know all there is to know about safety factors. We will help you find the exact wire ropes that will meet your requirements, no matter what project you have in mind.

SWL, NWL, MBS — all of the acronyms can get very confusing. Don’t fret – we’re here to clear things up when it comes to safe working load limits and the terms associated with it.

Safe Working Load (SWL) sometimes stated as the Normal Working Load (NWL) is the mass or force that a piece of lifting equipment, lifting device or accessory can safely utilize to lift, suspend, or lower a mass without fear of breaking. Usually marked on the equipment by the manufacturer and is often 1/5 of the Minimum Breaking Strength (MBS) although other fractions may be used such as 1/4, 1/6 and 1/10.[1][2][3]

Other synonyms include Working Load Limit (WLL), which is the maximum working load designed by the manufacturer. This load represents a force that is much less than that required to make the lifting equipment fail or yield, also known as the Minimum Breaking Load (MBL). SWL or WLL are calculated by dividing MBL by a safety factor (SF). An example of this would be a chain that has a MBL of 2000 lbf (8.89 kN) would have a SWL or WLL of 400 lbf (1.78 kN) if a safety factor of 5 (5:1, 5 to 1, or 1/5) is used.

Here at Industrial Rope Supply, we are not only committed to providing you with a quality product, but also with all the information needed to insure safety comes first on every job. Have safety questions on a product purchased from us? Contact us today and we’ll be happy to talk you through and/or provide you with the safety materials needed.

A lifting sling has a purpose, which is to move bulky, large, and heavy loads. Slings are used because lifting without them can be difficult and sometimes not even possible. Lifting slings makes a direct connection between the load and the lifting equipment being used. Although these slings are used to make lifting more accessible, they can make lifting more dangerous if the straps are misused. Anytime a sling is used for lifting, it is essential that users take concrete steps and precautions.

A lifting sling should be inspected before every use (including the first time). A damaged sling can break while lifting loads. Dropping loads can harm people, products, and the environment.

Different sling styles and sizes exist, and so not all can be used interchangeably. When it comes to lifting tools, you need the right sling for the job. Webbing slings have a full surface, which can help to protect larger loads.

Never exceed the working limit for a load. All lifting devices, like cranes and hoists, are rated for the weight they can carry. Lifting slings are calculated similarly. If you are lifting an object that is roughly 18 tonnes, you will want to acquire slings that have a WLL (working load limit) of 20 tonnes.

Original equipment wire rope and replacement wire rope must be selected and installed in accordance with the requirements of this section. Selection of replacement wire rope must be in accordance with the recommendations of the wire rope manufacturer, the equipment manufacturer, or a qualified person.

Wire rope design criteria: Wire rope (other than rotation resistant rope) must comply with either Option (1) or Option (2) of this section, as follows:

Option (1). Wire rope must comply with section 5-1.7.1 of ASME B30.5-2004 (incorporated by reference, see § 1926.6) except that section"s paragraph (c) must not apply.

Option (2). Wire rope must be designed to have, in relation to the equipment"s rated capacity, a sufficient minimum breaking force and design factor so that compliance with the applicable inspection provisions in § 1926.1413 will be an effective means of preventing sudden rope failure.

Type I rotation resistant wire rope ("Type I"). Type I rotation resistant rope is stranded rope constructed to have little or no tendency to rotate or, if guided, transmits little or no torque. It has at least 15 outer strands and comprises an assembly of at least three layers of strands laid helically over a center in two operations. The direction of lay of the outer strands is opposite to that of the underlying layer.

Type II rotation resistant wire rope ("Type II"). Type II rotation resistant rope is stranded rope constructed to have significant resistance to rotation. It has at least 10 outer strands and comprises an assembly of two or more layers of strands laid helically over a center in two or three operations. The direction of lay of the outer strands is opposite to that of the underlying layer.

Type III rotation resistant wire rope ("Type III"). Type III rotation resistant rope is stranded rope constructed to have limited resistance to rotation. It has no more than nine outer strands, and comprises an assembly of two layers of strands laid helically over a center in two operations. The direction of lay of the outer strands is opposite to that of the underlying layer.

Type I must have an operating design factor of no less than 5, except where the wire rope manufacturer and the equipment manufacturer approves the design factor, in writing.

When Types II and III with an operating design factor of less than 5 are used (for non-duty cycle, non-repetitive lifts), the following requirements must be met for each lifting operation:

A qualified person must inspect the rope in accordance with § 1926.1413(a). The rope must be used only if the qualified person determines that there are no deficiencies constituting a hazard. In making this determination, more than one broken wire in any one rope lay must be considered a hazard.

Each lift made under § 1926.1414(e)(3) must be recorded in the monthly and annual inspection documents. Such prior uses must be considered by the qualified person in determining whether to use the rope again.

Rotation resistant ropes may be used as boom hoist reeving when load hoists are used as boom hoists for attachments such as luffing attachments or boom and mast attachment systems. Under these conditions, all of the following requirements must be met:

The requirements in ASME B30.5-2004 sections 5-1.3.2(a), (a)(2) through (a)(4), (b) and (d) (incorporated by reference, see § 1926.6) except that the minimum pitch diameter for sheaves used in multiple rope reeving is 18 times the nominal diameter of the rope used (instead of the value of 16 specified in section 5-1.3.2(d)).

The operating design factor for these ropes must be the total minimum breaking force of all parts of rope in the system divided by the load imposed on the rope system when supporting the static weights of the structure and the load within the equipment"s rated capacity.

Wire rope clips used in conjunction with wedge sockets must be attached to the unloaded dead end of the rope only, except that the use of devices specifically designed for dead-ending rope in a wedge socket is permitted.

Prior to cutting a wire rope, seizings must be placed on each side of the point to be cut. The length and number of seizings must be in accordance with the wire rope manufacturer"s instructions.

Wire rope is often used in slings because of its strength, durability, abrasion resistance and ability to conform to the shape of the loads on which it is used. In addition, wire rope slings are able to lift hot materials.

Wire rope used in slings can be made of ropes with either Independent Wire Rope Core (IWRC) or a fiber-core. It should be noted that a sling manufactured with a fiber-core is usually more flexible but is less resistant to environmental damage. Conversely, a core that is made of a wire rope strand tends to have greater strength and is more resistant to heat damage.

Wire rope may be manufactured using different rope lays. The lay of a wire rope describes the direction the wires and strands are twisted during the construction of the rope. Most wire rope is right lay, regular lay. This type of rope has the widest range of applications. Wire rope slings may be made of other wire rope lays at the recommendation of the sling manufacturer or a qualified person.

Wire rope slings are made from various grades of wire rope, but the most common grades in use are Extra Improved Plow Steel (EIPS) and Extra Extra Improved Plow Steel (EEIPS). These wire ropes are manufactured and tested in accordance with ASTM guidelines. If other grades of wire rope are used, use them in accordance with the manufacturer"s recommendations and guidance.

When selecting a wire rope sling to give the best service, consider four characteristics: strength, ability to bend without distortion, ability to withstand abrasive wear, and ability to withstand abuse.

Rated loads (capacities) for single-leg vertical, choker, basket hitches, and two-, three-, and four-leg bridle slings for specific grades of wire rope slings are as shown in Tables 7 through 15.

Rated loads for a sling in a choker hitch are the values shown in Table 7, 9, 11, 13, 14, or 15, provided that the angle of the choke is 120 degrees or more (Fig. 2). Use the values in Fig. 2 or those from the sling manufacturer or a qualified person for angles of choke less than 120 degrees.

Ensure that slings made of rope with 6×19 and 6x37 classifications and cable slings have a minimum clear length of rope 10 times the component rope diameter between splices, sleeves, or end fittings unless approved by a qualified person,

Ensure that braided slings have a minimum clear length of rope 40 times the component rope diameter between the loops or end fittings unless approved by a qualified person,

Ensure that grommets and endless slings have a minimum circumferential length of 96 times the body diameter of the grommet or endless sling unless approved by a qualified person, and

Perform welding of handles or other accessories to end attachments, except covers to thimbles, before assembly of the sling. Ensure that welded end attachments are proof tested by the manufacturer or a qualified person. Retain the certificates of proof test and make them available for examination.

Do not use wire rope clips to fabricate wire rope slings, except where the application precludes the use of prefabricated slings and where the sling is designed for the specific application by a qualified person,

Although OSHA"s sling standard does not require you to make and maintain records of inspections, the ASME standard contains provisions on inspection records.[3]

Use damaged slings only after they are repaired, reconditioned, and proof tested by the sling manufacturer or a qualified person using the following criteria:

Ensure that wire rope slings have suitable characteristics for the type of load, hitch, and environment in which they will be used and that they are not used with loads in excess of the rated load capacities described in the appropriate tables. When D/d ratios (Fig. 4) are smaller than those listed in the tables, consult the sling manufacturer. Follow other safe operating practices, including:

Ensure that multiple-leg slings are selected according to Tables 7 through 15 when used at the specific angles given in the tables. Ensure that operations at other angles are limited to the rated load of the next lower angle given in the tables or calculated by a qualified person,

When D/d ratios (see Fig. 6) smaller than those cited in the tables are necessary, ensure that the rated load of the sling is decreased. Consult the sling manufacturer for specific data or refer to the WRTB (Wire Rope Technical Board) Wire Rope Sling Users Manual, and

Ensure that all portions of the human body are kept away from the areas between the sling and the load and between the sling and the crane or hoist hook,

When using a basket hitch, ensure that the legs of the sling contain or support the load from the sides, above the center of gravity, so that the load remains under control,

Ensure that the load applied to the hook is centered in the base (bowl) of the hook to prevent point loading on the hook, unless the hook is designed for point loading,

Before initial use, ensure that all new swaged-socket, poured-socket, turnback-eye, mechanical joint grommets, and endless wire rope slings are proof tested by the sling manufacturer or a qualified person.

Permanently remove from service fiber-core wire rope slings of any grade if they are exposed to temperatures in excess of 180 degrees F (82 degrees C).

Follow the recommendations of the sling manufacturer when you use metallic-core wire rope slings of any grade at temperatures above 400 degrees F (204 degrees C) or below minus 40 degrees F (minus 40 degrees C).

The LKING STEEL LIMITED 6 x 37 IWRC (independent wire rope core) single-leg wire rope sling has eye-and-eye endings and a mechanical splice for lifting loads with vertical, choker, or basket configurations in general industry applications. The 6 x 37 IWRC construction contains six strands of wire rope with approximately 37 wires per strand wrapped around a separate 7 X 7 wire rope, which has seven strands with seven wires per strand, in the center of the sling. This construction provides more flexibility than a 6 x 7 or 6 x 19 wire rope sling. The wire rope construction has more abrasion and heat resistance than a web sling. This eye-and-eye sling has an eye, or loop, on both ends, and can be used with vertical, choker, and basket lifting configurations. The eyes are secured with a mechanical (also called Flemish) splice that is stronger than a hand splice. This sling has a minimum D/d ratio of 25 and meets American Society of Mechanical Engineers (ASME) specification B30.9 and Occupational Safety and Health Administration (OSHA) specification 1910.184.

Slings are used to lift heavy objects for industrial applications. Types of slings include web slings, wire rope slings, chain slings, and mesh slings. The appropriate type of sling for an application depends on the strength-to-weight ratio, flexibility and resistance to bending, resistance to abrasion and cutting, resistance to crushing, resistance to stretching, and resistance to high temperatures and other environmental stressors. Slings have one, two, three, or four legs; or a continuous loop of webbing or wire rope. Legs are support branches that extend from a single point at the top of the sling to the item being lifted so the weight of the load is distributed evenly among the branches. Slings have eyes (loops) or alloy steel fittings on the ends.

A vertical lifting configuration connects a crane hook directly to a load with a single, vertical sling, usually by means of a hook. In a choker configuration, the sling wraps entirely around the load, and one loop passes through the other to form a slip noose, or choker. In a basket configuration, the sling passes under the load and both ends of the sling connect to the crane hook. Load capacity is the maximum weight to be lifted in a vertical configuration. The capacity in a choker configuration is approximately equal to the vertical capacity times 0.8. The capacity in a basket configuration, with sling ends at a 90-degree angle, is approximately equal to twice the vertical capacity. Load capacity in a basket configuration decreases if the angle of the sling is less than 90 degrees. For example, a sling with a capacity of 2,000 lb. in a vertical configuration will have an approximate capacity of (2,000)(0.8)=1,600 lb. in a choker configuration and an approximate capacity of (2,000)(2)=4,000 lb. in a basket configuration, if the sling ends are at a 90-degree angle to the load. A wire rope sling"s capacity in a basket configuration applies only when the configuration meets the sling"s minimum D/d ratio, which is the ratio of the diameter of the rope"s curve around the load (D) to the diameter of the sling (d). If the minimum D/d ratio is not met, the capacity of the sling is decreased.

LKING STEEL LIMITED Lifting Technologies manufactures lifting solutions including slings, cranes, and hoists. Founded in 1967, the company is headquartered in Shanghai, China.

B) if the 2legswire rope sling, the hanging points should be on both sides of the goods and the hooks are above the center of gravity of the suspended objects.

C) if it is three legs or four legs wire rope sling, the hanger must be proportioned on the plane around the cargo and the hook is located directly above the center of gravity of the suspended object.

Working load limit is also known as safety working load, abbreviated as W.L.L, it is the maximum safe working load that a piece of lifting equipment, without fear of breaking. It usually varies based on what type of rigging or safety equipment and are identified by manufacturers.

The minimum break strength aka Minimum Breaking Load (MBL) refers to the required force at which your load equipment will fail. It is expressed in pounds, and/or tonnes, and will actually fail if you go over the guaranteed strength.

So if a shackle has a WLL of 1 ton, would have a SWL or MBS of 4 tons if a safety factor of 4 (4:1, 4 to 1, or 1/4) is used, usually the safety factor ranging from 4 to 6 on lifting equipment.

You can leave your comment below to answer the questions. If you still have any questions or comments, please feel free to contact us at info@hilifting.com.

My name is William Yang, I’m the business manager of Hilifting. I have been in Rigging industry for more than 10 year. Feel free to contact us. I’m happy to provide you the best service and products.

Wire rope is constructed of multiple strands of wire that are twisted and braided together to form a spiral design or helix. Once the separate wires are shaped into a solid form, they become a single wire with greater strength because the individual wires equalize pressure and have greater flexibility than the individual strands.

To further enhance the strength of wire ropes, they are grouped and wound together to produce cables, which adds to their usefulness as a means of support, ability to lift, and give structural stability.

A key factor in wire rope is the lay of the strands, which can be regular or lang. With regular lay, or right and ordinary lay, the strands are wound from left to right with the wires laid in the opposite direction of the lay of the strands. With lang lay, the wires are wound in the same direction.

The structure and design of wire rope produces a final product that has superior strength, excellent strength flexibility, and the ability to handle constant bending stress as well as being weather resistant.

Wire rope is one of those products that has found a place in a wide variety of industries since it can be adapted and shaped to fit several applications. It can be found as a tow cable for boats and airplanes or in the movie industry as a harness for stunt artists. The varied uses of wire rope have made it an essential part of operations that require a rope with strength, endurance, and flexibility.

In the aerospace industry, wire ropes, or Bowden cables, connect pedals and levers in the airplane cockpit to send power to aircraft systems to control the airplane. The things that are controlled by wire ropes are propeller pitch, cowl flaps, and throttle. Wire ropes on aircraft are insulated to avoid vibrations.

Wire rope is extensively used in the auto industry for a wide variety of applications due to its versatility and strength. It is used for raising windows and opening and closing sunroofs. Other uses include steering wheels, cables, exhausts, springs, sunroofs, doors, and seat components. In the manufacturing process, wire rope is used to hoist vehicles, move large body parts, and on hoists and cranes.

The construction industry has a greatest reliance on wire rope because of the need to lift and lower heavy loads. Wire rope used in construction must have extremely high strength and exceptional performance for safety reasons and efficiency. Larger versions of wire rope are used for suspension bridges and supporting concrete columns.

The main use of wire rope in food processing is for lifting, moving loads, and other heavy tasks. Finished products or raw materials require being moved in storage units and processing centers. The strength and endurance of wire rope makes it possible to move these materials. Wire rope for food processing must be able to withstand regular chemical cleaning.

As with other industries, the oil and gas industry needs strong and reliable equipment for moving heavy equipment. In ocean drilling, machinery is dropped into the ocean using wire rope to securely hold devices to be dropped to extreme depths. Wire ropes are designed to withstand the extreme pressure and stress required. A further use of wire ropes for drilling operations is to maintain stability in the drilling lines. One of the unique features of oil rig wire rope is its length, which can exceed 10,000 feet.

A very common use for wire rope is mooring and towing of sea and freshwater boats and vessels. In the shipbuilding industry, wire rope is used to secure lifeboats as well as lower them into the water. On sailboats, wire rope is used to lift and lower sails. The benefit of using wire rope is its resistance to corrosion and rust caused by salt water and ocean mist.

The skiing industry, much like heavy equipment industries, uses wire rope to hold cars, lifts, or chairs to transport skiers up the mountain. This type of wire rope comes in several varieties depending on the size of the mountain. The benefits of wire rope for skiing is its dependability, guaranteed safety, and reliability. The main challenge of wire rope for use in sports is the weather conditions it must endure.

Since the beginnings of amusement parks, wire rope has been an essential part of attraction construction. It is used to bring roller coaster cars to the top of the ride, hold swings, and pull various vehicles through attractions. One of the main concerns of public amusement parks is safety since rides are filled with powerful machinery designed to operate continuously.

Making the dangerous and exciting shots in movies requires well planned safety precautions. One of the aspects of that planning is wire rope that is designed to protect performers when they are engaged in dangerous and life threatening shots. Dependable wire ropes are ideal since they have the flexibility, strength, endurance, and versatility to be adapted to any conditions.

In architecture and design, wire rope has been used for guard rails, balustrades, and roof construction. In innovative green buildings where plants grow along the surface of the building, the plants grow along specially designed vertical wire ropes that are capable of withstanding weather conditions.

A common use of wire rope is in railings, which are safe, durable, and provide a pleasing aesthetic appeal. The use of wire rope for railings provides protection without obstructing the view from a building. This aspect of wire rope is one of the reasons that it is used for large architectural projects since it blends into the structure without interiors with the architectural design.

The types of wire rope are determined by the number of wires in each strand and how many are in the rope, which is defined by a two number system with the first number being the number of wires and the second being the number of wires in each strand. For example, a 6x19 wire rope has 6 wires in 19 strands.

There are a wide variety of products that are produced using wire rope. The demand for wire rope products is due to its strength, durability, and reliability. Since the basic purpose of wire rope is to lift and move heavy materials and items, the most common type of wire rope product is the wire rope sling.

Though the construction of wire rope slings is very similar for all types, there are certain variations applied to slings to adjust them to fit different applications. Slings are configured in various ways to fit different types of loads. These changes are referred to as hitches.

Choker Hitch: In the choker configuration, one eye of the sling is attached to the lifting hook. The second eye is looped over the first sling eye to form a noose shape or choke. The load is placed in the choke loop.

Bridle Hitch: The multiple leg or bridle hitch style has more than one wire rope sling attached to equalize the load and control balance. They reduce load damage by using fixed points on the load and offer easier rigging when hooked into fixed lifting points. .

Single Part Wire Rope Sling: The eye for a single part wire rope sling is formed by looping the wire rope back on to the rope. The end of the rope is attached by a clamp or being woven by hand or mechanically into the rope body. Single part wire rope slings use a single wire rope to produce the sling.

Braided Wire Rope Sling: A braided wire rope sling is made by braiding wire ropes to form a sling. The increased number of strands enhances the strength of the sling and its load capacity. Braiding can be done with three to nine wire ropes.

Cable Laid Wire Rope Sling: Cable laid wire rope slings are made from combining several smaller wire ropes to form a flexible, easy to handle, and kink resistant sling.

Woven Eye Wire Rope Sling: For the woven eye version of a wire rope sling, the eye is formed by weaving the wire rope into itself after forming the loop. It is designed to reduce the chance of the sling catching or being hung up when lifting.

Thimble Wire Rope Sling: To add to the strength of wire rope slings and lessen the stress on a small area of the eye, a thimble, a U shaped piece into which the wire rope fits, is placed in the eye, which helps the sling to retain its natural shape. The thimble is positioned to prevent the hook or load from coming in contact with the wire rope.

Endless Wire Rope Sling:Endless wire rope slings are adaptable slings without a set wear point. They can be manufactured in a wide range of sizes and are used in applications where headroom may be a problem. Endless wire rope slings are made by splicing the ends of a piece of wire rope together or by tucking strand ends into the body to form a core with a tucked position the opposite of the core position. They are also referred to as grommet wire rope slings.

Coiled wire rope is made from bundles of small metal wires that are twisted into a coil. It comes in many varieties and is easy to store since it does not require a spool. Coiled wire rope is produced in coils. When it is not in use, it springs back into a coil, which makes it easy to handle.

Cable wire rope is 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.

Push pull wire rope assemblies are used to send force and are used in the aircraft, exercise, medical, automotive, and office equipment industries. Unlike using a single heavy wire, push pull assemblies made with wire rope are stiffer and have a larger bend radii for smoother motion of the wire.

Wire rope assemblies include wire rope and various parts and components that have been added to the wire rope to enhance its function. The connectors for a wire rope assembly are designed to connect the assembly to hooks, equipment, or machines as well as other wire rope assemblies. The central part of a wire rope assembly is the wire rope, which determines the type and kind of work the assembly can perform.

Wire rope lanyards are a standard wire rope product that have a multitude of uses. They are produced using the same process that is used to produce wire rope with the same numbering categorizing system. Lanyards are used to hold fasteners, hardware, or components to prevent loss of an item or prevent injury.

As can be seen in the image below, lanyards come with a variety of connectors to specifically fit an application. Custom designed lanyards are designed for unusual and unique functions where a standard lanyard will not fit. The variety of connectors allows the lanyard to be easily connected.

Ends Fittings or Terminals: The nature of the end fitting depends on the function of the lanyard. All manufacturers have a wide assortment of end fittings to choose from. They include stamped eyes, ball ends, ball shanks, stops, sleeves, thimbles, threaded studs, and strap forks and eyes, to name a few. The image below has a few examples of end fittings terminals.

In many ways, wire rope is a form of machine with multiple moving parts. Normally, when we think of a machine, we imagine a device with a motor, drives, and gears. Wire rope does not have any of those components but does fit the definition of being a complex mechanism. It has moving parts that work together to move heavy materials and loads.

The main function of wire rope is to do heavy lifting, which is very dependent on wire rope slings. The type of sling is determined by the quality of the wire rope used to form them and whether several ropes have been braided or wound together.

Wire is the smallest part of wire rope but makes up the various strands. The composition of the wire can be steel, iron, stainless steel, copper, or other types of metal wires and are produced in different grades. The individual wires can be coated or bright, meaning uncoated.

Strands are sets of wires that are twisted together and are placed in a helical pattern around the core. The size of the wire determines its abrasive qualities with larger wires being more abrasive and less flexible than smaller ones.

The core is the center of the wire rope and serves as a support for the strands and helps the wire rope keep its position when it is under stress or bearing a load.

Lubrication is applied during the manufacturing process to reduce friction between the wires and strands as well as protection from corrosion and rust. The tight winding of the wires enhances the ability of the wire rope to retain the lubrication which is essential to its longevity.

The purpose of applying lubricant is to limit the friction between the cables to increase the useful life of the wire rope. In certain applications, such as space travel, lubricants can be hazardous and cause equipment to malfunction. In those instances, non-lubricated wire rope is used, which is referred to as dry wire rope or cable.

Of all of the products that are made from wire rope, slings are the most common and widely used. These looped wire ropes come in different varieties and grades depending on the type of wire used. Also, to enhance wire sling performance, several wire ropes may be wound together to form a sturdier and more reliable sling.

Flemish splicing is a method for repairing a wire rope and involves breaking the wire rope in half and tying it back together. In the Flemish method, the wire rope is tied back on itself and swaged down a sleeve over the unbroken wire rope to create the new eye.

Prior to placing the wire rope into the holding device used to shape the eye, a steel compression sleeve is placed on the rope, which will be used to secure and hold the eye.

Once the proper size is achieved, the unwound strands are rewound in the reverse order of their former positioning. If the wire rope has a right hand lay, it is rewound using a left hand lay. The opposite is true if the wire rope has a left hand lay, then it is rewound using a right hand lay. By using this technique, a friction mold is formed for the splicing of the sling.

Anti-rotational wire rope resists the forces of rotation by having opposing layers of helical stands. By winding the wire rope with oppositional strands, the wire rope is guaranteed to not unwind in clockwise or counterclockwise directions. The key to anti-rotational wire rope is to ensure that the outer diameter is static.

In the manufacture of anti-rotational wire rope, counter stranded filaments have vacant spaces between them. To make the wire rope anti-rotational, it is tightly twisted in the counterclockwise direction, which tightens the spaces between the filaments. If the wire rope is turned in a counterclockwise direction, the strands tighten around each other creating a spring force.

The tails and stray wires of the wire rope have to be straightened and properly formed before applying the compression sleeve. Once the sleeve has been placed, it is carefully checked to be sure that it is accurately engaged.

Prior to placing the wire rope sling in the swaging die, the die has to be thoroughly lubricated. Once the die is set, the wire rope‘s compression sleeve and the wire rope are compressed using several hundred thousand pounds of force. The swaging process alters the dimensions of the wire rope and compression sleeve to form a tight connection for the correct diameter for the sling connection. As force is applied, the compression sleeve is turned so that pressure is evenly applied.

There are several types of metal wires that are used to produce wire rope, which include steel, stainless steel, galvanized, aluminum, nickel alloy, bronze, copper, and titanium. Carbon steel is the most common type of wire rope material.

Wire ropes are made using uncoated bright wire, which is high-carbon steel. The type of steel depends on the requirements of the wire and its tensile strength and its fatigue and wear resistance.

Galvanized wire rope is treated with zinc to prevent corrosion and can be used in harsh conditions and environments. It is a cost effective alternative to stainless steel but does not have the same corrosion resistance. Galvanized wire rope is stronger than stainless steel of the same grade and size. Vinyl coated galvanized wire rope is easy to handle and flexible.

Stainless steel wire rope is corrosion and rust resistant. It is available in types 316 and 304 with 316 having greater corrosion resistance. Stainless steel wire rope can be used for marine applications, acidic environments, and other demanding conditions. It is produced with the appropriate tolerances and composition to meet the needs of the application.

Multiple strands of copper are braided into a round hollow shape, which is pressed into the desired width and thickness. Copper wire rope has exceptional flexibility, an exceptional life span and can be used as part of electrical components.

Bronze wire rope inhibits sparking and is corrosion resistant. It is made from preformed wire to ensure that it maintains its shape and does not unravel when cut. Bronze wire rope is abrasion resistant and very flexible with a crush resistant core.

Inconel wire can be used in applications that reach temperatures as high as 2000° F and is oxidation and corrosion resistant. It is non-magnetic and has excellent resistance to chloride based corrosion cracking. Inconel wire rope can be used with nuclear generators and chemical and food processing.

Titanium wire rope comes in several grades with grade two being 99% pure. It is easily formable and weldable. Titanium wire rope is commonly used in chemical processing and marine hardware.

For wire rope to perform properly, it needs to have proper care. Wire rope is an essential tool necessary to perform a wire range of lifting and moving jobs. It is important that it be handled, treated, installed, stored, and treated correctly to prolong its life and perform to the highest standards.

Seizing should be completed on both ends of the wire rope, which will protect it from loosening. If this is done improperly, the wire rope can become distorted. Wire rope that is properly seized evenly distributes the load.

Wire rope is stored on reels or coils and has to be carefully handled when it is being removed. To ensure excellent performance, the wire rope should not be dropped during removal. If the reel or coil is dropped or damaged, it can make handling the wire rope difficult and cumbersome. As the wire rope is removed from the reel, check to see that the reel is rotating as the wire is removed.

Wire rope is depended on for heavy lifting and is trusted to keep a load and people safe. As with all heavy duty equipment, wire rope must have a regular inspection schedule and be visually assessed during use.

Broken Strands – An easy way to check for broken strands is to run a cloth over the length of the wire. Broken strands that are found in critical areas, such as parts that pass through pulleys or sections that are regularly flexed, rubbed, or constantly worked must be replaced and repaired.

Internal wear – This can be tested by flexing the wire rope, which indicates if the interior has deteriorated, experienced fatigue, or become distorted.

For wire rope to perform at the highest level, it has to be stored in a well ventilated environment that is dry, covered, and not in contact with the floor. The avoidance of high moisture or damp conditions is an absolute necessity. While the wire rope is in storage, it should be moved regularly to keep the lubricant from wearing off.

Though lubricant is applied during the manufacturing of wire rope, it wears off during use. Lubrication is the key to the performance of wire rope because it helps prevent abrasion as the wires rub against one another. Relubrication should be applied after the original lubricant has worn off.

Wire rope is a tool and must be cleaned regularly as with any form of machinery. This can be accomplished with different types of petroleum solvents and a wire brush. Mechanical methods of cleaning can include compressed air or a steam cleaner. Once the cleaning process is completed, the wire rope should be lubricated for protection.

There are several substances that can harm a wire rope. They include salt water, brine, acid, various gasses, and humidity. To avoid the intrusion of these negative effects, when a job is completed and the wire rope is to be stored, it should be cleaned, lubricated, and placed in proper storage.

When wire rope is being removed from a spool or being spooled, the operation must be performed smoothly with the spool rotating at a constant speed and rhythm. This will help prevent kinking or binding.

When a wire rope shows a reduction in diameter, has broken wires, kinks, nodes, flattened surfaces, out of place outer wires, damage from heat exposure, corrosion damage, or the formation of unexpected loops, it should be removed and replaced or be repaired.

Wire rope is regulated by the Occupational Safety and Health Administration (OSHA) as part of the regulations for cranes and derricks in construction as part of 29 CFR 1926.1413, which went into effect on November 8, 2010.

The inspection of wire ropes is on three levels: shift, monthly, and annually. Shift and monthly inspections can be completed by an approved operator, while annual inspection must be completed by certified personnel.

As with the shift and monthly inspections, the annual inspection follows the guidelines for the shift inspection. This inspection must be completed by certified personnel. The entire surface of the wire rope has to be inspected, with attention to:

Annual inspections can be excused if it is not possible due to the wire ropes setup or configuration or the location of the work site. It must be completed within six months. If any deficiencies are found, the wire rope must be repaired or removed. For some deficiencies, it is possible to keep the wire rope in use but have them regularly monitored.

Wire rope is a form of metal tool that is constructed of multiple strands of wire that are twisted and braided together to form a spiral design or helix.

To further enhance the strength of wire rope, they are grouped and wound together to produce cables, which adds to their usefulness as a means of support, ability to lift, and give structural stability.

The types of wire rope are determined by the number of wires in each strand and how many are in the rope, which is defined by a two number system with the first number being the number of wires and the second being the number of wires in each strand.

The goal of a sling inspection is to evaluate remaining strength in a sling which has been used previously to determine if it is suitable for continued use.

Specific inspection intervals and procedures are required by the Occupational Safety and Health Act (OSHA) and by ANSI B30.9 Regulations, and the responsibility for performance of inspections is placed squarely upon the sling user by Federal Legislation.

As a starting point, the same work practices which apply to all “working” wire ropes apply to wire rope which has been fabricated into a sling.Therefore, a good working knowledge of wire rope design and construction will be not only useful but essential in conducting a wire rope sling inspection.

But because wire rope is a rather complex machine, no precise rules can be given to determine exactly when a wire rope sling should be replaced. There are many variables, and all must be considered.

Broken Wires: For single-part slings. 10 randomly distributed broken wires in one rope lay, or five broken wires in one strand on one rope lay. For multi-part slings these same criteria apply to each of the component ropes.For the inspection, a broken wire shall only be counted once; that is, each break should have two ends.

Metal Loss: Wear or scraping of one-third the original diameter of outside individual wires. This is quite difficult to determine on slings and experience should be gained by the inspector by taking apart old slings and actually measuring wire diameters.

Distortion: Kinking, crushing, birdcaging or other damage which distorts the rope structure. The main thing to look for is wires or strands that are pushed out of their original positions in the rope. Slight bends in a rope where wires or strands are still relatively in their original positions would not be considered serious damage. But good judgement is indicated.

Bent Hooks: No more than 15 percent over the normal throat openings, measured at the narrowest point, or twisting of more than 10 degrees is permissible.

Metal Corrosion: Severe corrosion of the rope or end attachments which has caused pitting or binding of wires should be cause for replacing the sling. Light rusting usually does not affect strength of a sling, however. In addition to these seven conditions specified by OSHA, the following are also important:

Pulled Eye Splices: Any evidence that eye splices have slipped, tucked strands have moved, or pressed sleeves show serious damage may be sufficient cause to reject a sling.

Unbalance: A very common cause of damage is the kink which results from pulling through a loop while using a sling, thus causing wires and strands to be deformed and pushed out of their original position. This unbalances the sling, reducing its strength.

Disposition of Retired Slings: the best inspection program available is of no value if slings which are worn out and have been retired are not disposed of properly. When it is determined by the inspector that a sling is worn out or damaged beyond use, it should be tagged immediately DONOTUSE. This sling should then be destroyed as soon as possible by cutting the eye and fittings from the rope with a torch. This will help assure that an employee will not mistakenly use a sling which has been retired from service.

Dynamica rope slings have an integrated splice connecting the rope into the sling. The elongation of a spliced rope is caused by the alignment of the fibres in the splice under tension. The sub strands and strands of the rope in the splice align when the rope sling is loaded. The elongation caused by splice setting can be removed by Proof Loading in our Test Bed. All rope slings made by Dynamica Ropes are Proof Loaded up to 500 t in our in-house Test Bed or at external facilities, if the Proof Load exceeds 500 t.

By Proof Loading the slings before use you are sure that the rigging you are going to use has a correct working load limit (WLL) but also is prepared if an unexpected situation occurs.

Choosing a Proof Loaded sling you make a safe choice, as the Proof Loading is our guarantee to you, that the heavy duty lifting sling can carry the load, which it is designed for.

Dynamica Ropes has an in-house Test Bed equipped with an extensometer that allows measuring the exact elongation of our rope slings made with HMPE/Dyneema®.

With the know-how based on the empiric testing, we can make very precise EWL calculations on SafeLift slings. This means that we are able to manufacture rope slings with a very low EWL tolerance.

The EWL tolerance of our SafeLift Rope Slings is always according to DIN EN 1492-4, which states an EWL tolerance of 3 %. Since we often deliver our rope sling solutions for engineered lifting, the EWL tolerance of maximum 1 % or even less is often agreed for a specific rope slings.

All rope slings are Proof Loaded according to DNV-ST-N001 and delivered with a Proof Load Certificate stating the EWL of the rope sling measured under tension.

Large Loads Require Large Slings Whatever the load you are lifting. YuanBo Wire Rope Factory can supply a steel wire rope sling to do the task. Sling up to 12" (305mm) diameter can be supplied with minimum braking loads up to tons. There arethree distinct types of Wire Rope Sling.

Slings manufactured from cable laid ropes, 4" diameter to 12" diameter. hand spliced or by combination of hand splicing and socketing with eye at each end.

Slings manufactured from 6 strand equal laid ropes. up to 3.5 " diameter with soft eyes spliced each end. terminated by either hand splicing or mechanical means.

The most common size: wire rope slings having soft eyes at both end used for heavy lifting operations with safety factor of 7, length 6m, 12m, 16m, 20m, and the swl from 5 ton to 40 ton.

Wire rope slings have played a critical role in applications like lifting, rigging, and hoisting. They are usually made from galvanized or un-galvanized steel wire strands, which are woven into ropes with end terminations. The end terminations can be loops or hooks.

Several industries, such as mining, manufacturing, shipping, and power generation, use wire rope slings because they are easy-to-use, cost effective, and reliable. Depending on the type of load and crane, you can use an assembly of wire rope slings for lifting, rigging, and hoisting.

Although they are extremely strong and durable, wire rope slings require regular maintenance and inspection. They must be inspected to ensure safety and prevent economic losses. In this short guide, we will take a look at wire rope sling inspection, maintenance, and replacement.

As mentioned before, the purpose of wire rope sling inspection is to identify any damage or excessive wear before it leads to a disaster. Two leading organizations in the US, OSHA, and ASME have published inspection and maintenance guidelines to ensure wire rope slings safety and functionality.

The two standards governing the criteria and guidelines of wire rope sling inspection are OSHA 1910.184 and ASME B30.9. As per these guidelines, there are three types of inspections.

This inspection should be carried out immediately after receiving the wire rope slings. During this inspection, make sure to check the sling identification tags. These tags will bear the product information, its rated load capacity, and other specifications. Check if they are what you ordered and what you need.

The second type of wire rope sling inspection is to be carried out daily or prior to use. As wire rope slings are used in a wide range of applications, it is always better to inspect them before each use. In other words, if you are going to use a sling three times a day, you should inspect it three times.

As wire rope slings can get damaged during a loading or rigging application, this inspection is extremely critical. You can have designated personnel, usually a competent crew member, to inspect wire rope slings before each use.

Only a certified professional or service provider can carry out periodic inspections. You also need to document each periodic inspection and maintain records, as per the ASME B30.9 guidelines. The schedule of periodic wire rope sling inspection depends on factors like frequency of use, the severity of work conditions, type of lifting or rigging, and experience gained on the service life of wire rope slings used in similar applications.

Even though it’s usually a visual inspection, you have to be thorough with it. Neither OSHA nor ASME has specified any fixed sling inspection process. You need to set up a process of your own based on your requirements, rope sling usage, and other factors.

If possible, maintain a detailed record of all your sling inspections. Well-kept records make it easier to identify slings that are nearing the end of their service life or are damaged.

Sling tag identification is the most critical step in sling inspection. These tags help you identify the usage specifications of the slings. So, make sure to maintain the tags in excellent condition throughout the lifespan of the slings. If the tag is damaged or illegible, remove the sling from use immediately.

If you come across any of the following scenarios during your sling inspection, you will need to remove the slings immediately. Furthermore, if you are unsure of the potential damage, discontinue the use of slings.

As mentioned before, the tag bears all the vital information and specifications. If the tag is missing or illegible, it’ll be impossible to know the rated load capacity of the sling. If you end up using it for a load higher than the rated capacity, it can lead to an accident.

Wires: Wires are made from materials like steel, iron, bronze, and stainless steel. Wires surround the core, and they come in different sizes and strengths.

Distortion constitutes damages like kinking, crushing, and birdcaging, among others. If you see any such damage or wires and strands pushed out of their original positions, you need to replace the wire rope sling immediately.

Wire rope damage due to heat results in metallic discoloration, fusing of wires, or loss of lubricant. Make sure to replace the sling if there is heat damage.

If you see bent hooks with twisting exceeding 10 degrees or normal throat openings (measured at the narrowest point) exceeding 15%, you need to replace the sling.

While light surface rust will not affect the strength of wire rope slings, you will need a replacement if the corrosion has caused pitting or binding of wires.

When using wire rope slings, pulling through a loop can push out wires and strands from their original positions, pushing the slings out of balance. If you see this damage, replace the slings immediately.

Kinks are nothing but loops with permanent wire and strand distortions. As this type of damage is irreparable, you need to replace the slings right away.

Improper use of wire rope slings can cause doglegs, which are permanent bends. If the slings have minor doglegs with no strand distortion or if you can’t see them when the sling is under tension, you can continue using the sling. However, replacement is necessary if the doglegs are severe.

Make sure to discard the damaged wire rope slings in an eco-friendly manner. You should label the slings “Do Not Use” to avoid accidental use. Then, you should cut the eye and fittings from the rope, cut the rope into 3’ to 4’ sections, and send them for recycling.

The third most important step is wire rope sling maintenance. You should keep the following points in mind to ensure regular and comprehensive maintenance:

Wire rope slings play a critical role in a wide range of industries such as mining, manufacturing, and shipping, among others. Although they are strong and have a long lifespan, rope slings do need regular inspection and maintenance to ensure safety and longevity. Hopefully, this guide will help clear all your doubts regarding wire rope sling inspection, replacement, and maintenance. If you need help with any rigging equipment inspection, maintenance, and replacement, feel free to reach out to our team at Holloway Houston Inc.

The load which a new wire rope may handle under given operating conditions and at an assumed design factor. A design factor of five is chosen most frequently for wire rope. (Operating loads not to exceed 20% of catalog breaking strength). Operating loads may have to be reduced when life, limb, or valuable property are at risk, or other than new wire rope is used. A design factor of 10 is usually chosen when wire rope is used to carry personnel. (Operating loads not to exceed 10% of catalog breaking strength). Responsibility for choosing a design factor with the user.

Rope sockets, thimbles, sleeves, hooks, links, shackles, sheaves, blocks, etc., must match in size, materials and strength, to provide adequate safety protection. Proper installation is crucial for maximum efficiency and safety.

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Working Load Limit (WLL) is the maximum working load designed by the manufacturer. This load represents a force that is much less than that required to make the lifting equipment fail or yield. The WLL is calculated by dividing the breaking load limit (BLL) by a safety factor (SF). An example of this would be a chain that has a BL of 2,000 lb. WLL of 400 lb. if a safety factor of 5 (5:1, 5 to 1, or 1/5) is used.