wire rope ips brands

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Interested in becoming a distributor for Miami Cordage/Florida Wire & Rigging Works? Whether you have a brick-and-mortar store or are an on-line retailer, we offer substantial discounts to our loyal distributors. Click here to find out more information.

In the past (pre 19th century), most heavy haulage and lifting needs were met by bulky chains or big ropes made of fiber. In the early 1830’s, a mine in Germany dropped a mine conveyance full of ore to the bottom of their mine and it was found that the heavy chains they were using to haul the conveyance to the surface suffered from work hardening and became severely brittle, leading to its failure.

As time progressed, other nations and people began to experiment with the fabrication of wire rope and, initially, each of them were essentially drawing hot steel through some dyes to create wires which were then laid helically together to form the wire rope. The type of steel that was readily available at the time was the same steel used to create ploughs for agriculture; thus the “Plough Steel” designation was used to denote what grade of steel was used to fabricate the rope.

Improvements were made to the ingredients of Plough Steel that allowed for a higher tensile strength of the wire rope. This new grade was aptly named, “Improved Plough Steel” or I.P.S. for short. Improved plough steel became the de facto steel to be used until it was once again improved upon, to the point where it is actually difficult to find Plough Steel grade wire rope in inventory at a sling shop.

Speaking of improvements made to the already Improved Plough Steel, once the recipe was perfected and it was found that wire rope could be made to have some extra strength. What did the powers that be name this new and improved wire rope…You guessed it, “Extra Improved Plough Steel.” EIPS offers approximately 10-15% increases in tensile strength over the old IPS depending on diameter. The higher tensile strength improves the minimum breaking strength of the wire rope. This, of course, will change the breaking strengths of the rigging mines and other industrial uses. This makes it important to know what type of wire rope your rigging is constructed from. If for example, a worker is referencing a sling chart for minimum breaking strength of a sling they should:

Currently, most rigging shops have transitioned to EIPS or are in the process of doing so. EIPS wire rope should be the standard in a modern day rigging shop and used for rigging such as wire rope slings, winch lines, and wire rope assemblies.

Northern Strands has been a locally owned company for over 50 years. We carry the largest supply of wire rope and rigging in Saskatchewan. Contact us today for a rigging quote or visit our showroom.

There are many different sizes, configurations, and materials that form wire rope, and these are different types including stainless steel wire rope, galvanized wire rope, and bright wire rope.

Looking for accessories to use with wire ropes? Our rigging supplies include hardware and accessories for use with cranes, hoists & winches, and oilfield applications.

Diameter:To properly measure the diameter of steel wire ropes, measure the rope at its widest point. This is an industry standard with wire cable manufacturers and steel cable suppliers.

Grade of Steel – EIPS, EEIPS: EIPS is Extra Improved Plowed Steel and has roughly 10% more strength than IPS. EEIPS is Extra Extra Improved Plowed Steel and is approximately 10% stronger than the EIPS. We offer every variety of EIPS Wire Rope and have a one day lead time on any EEIPS ropes.

Direction of Lay: Right hand and left hand designates which way the strands wrap around the core of the steel rope. Regular lay and Lang lay specify which way the wires are formed in the helix pattern. Regular lay means the wires are rotated opposite the direction of the strands around the core. Lang lay means the wires are twisted in the same direction as the strands are wrapped around the wire rope core.

Finish – Bright Wire, Galvanized Wire, and Stainless Steel: Most wire ropes have a bright, self-colored finish hence the name. Wire ropes generally have a coating of lubricant to reduce friction and protect from corrosion. However, there are wire ropes that are galvanized, stainless steel, or coated in vinyl and other plastics.

Material of the Core: Fiber Core (FC) or Independent Wire Rope Core (IWRC) – Fiber cores are made of natural (sisal, etc.) or synthetic (polypropylene, etc.) fibers and allow for increased flexibility. IWRC offers more support to the outer strands, and have a higher resistance to crushing. IWRC also offers more resistance to heat, reduces the amount of stretch, and increases the strength of the rope.

Strands: Another variable in wire rope is how many strands make up the rope and how many wires make up one strand. For instance, a 6×26 wire rope has 6 strands around a core with 26 wires making up each strand. The 6×19 class is the most common and offers higher resistance to abrasion whereas the 6×37 class offers higher flexibility.

Although there are exceptions for special applications, the constructions in 6×36 classification are primarily designed to be the most efficient for each rope diameter. As the rope size increases, for instance, a large number of wires can be used to achieve required fatigue resistance, and still those wires will be large enough to offer adequate resistance to abrasion.

The 6×19 classification of wire ropes includes standard 6 strand, round strand ropes with 16 through 26 wires per strand. This is a good rope to withstand abrasion or crushing on the drum. Ropes with independent wire rope strands and a core (IWRC) in general, are more crush resistant than fiber core ropes.

When you purchase our 6×19 Class of wire ropes, you get more than just another rope. Manufactured in an ISO 9001 certified factory and backed by the industry’s largest staff of professional engineers, we do more than meet published specifications.

The 6×26 WS has better resistance to abrasion than a 6x25FW. It features a compact construction with solid support for the wires; therefore it has a high resistance to crushing. Its number and relative size of the inner wires add to the stability of the strand and gives it a fatigue resistance comparable to a 6×25 FW. A standard 6×26 WS construction provides the best rope for a wide range of applications. In general, we recommend the use of the 6x26WS in any application where a 6x25FW is used.

Mast Raising Lines, also called Bull Lines or Bridle Lines, are usually two pieces: each having sockets on both ends. These lines can be fabricated from either right regular lay rope or right lang lay rope. They must be fabricated from IWRC ropes.

Premium ropes may be used for specific applications. PFV cushions the strands, distributes internal stresses, keeps in wire rope lubricant and keeps out dirt and debris, extending the service life.

Flex-X® 9 features compacted strands and swaging for extra drum crushing resistance and increased stability. Its high-density strands deliver extra strength and resistance to abrasion. Flex-X® 9 is manufactured with a dual compaction process to produce a compact cross-section with minimum voids and greater surface area on outer wires that contact drums, sheaves and the rope, itself during operation. The high-density compacted strands minimize nicking at strand-to-strand contact points. Flex-X® 9 was specifically designed for boom hoist applications and tubing line applications where drum crushing is a challenge.

Flex-X® 6 users receive superior performance and increased service life in many applications compared to the ropes they had previously employed. When compared to conventional six-strand ropes, Flex-X® 6 ropes provide greater surface area and more steel per given diameter. This increases rope stability and strength. This results in a longer service life and less sheave and drum wear.

Flex-X® 19, a Category 2 rotation resistant rope, is made from 19 strands. Six strands are laid around a core strand in one direction, and then 12 strands are laid around this first operation in the opposite direction. Because of its tightly compacted smooth design, Flex-X® 19 offers more crushing resistance than standard 19×7 rope, higher strength-to-diameter, resistance to bending fatigue, exceptional stability, reduced wear to sheaves and drums, and improved handling, operating and spooling characteristics.

A wire rope is a type of cable that includes several wire strands laced together to form a single wire. Generally, both the terms “wire” and “rope” are used interchangeably with “wire rope”; however, according to the technical definition, to be labeled a wire rope, the cable must have a thickness of at least 9.52 mm. As a versatile, high load capacity alternative to natural fiber ropes such as hemp and manila, wire rope provides motion transmission through nearly all angles, tie down, counterbalance, guidance, control, or lift.

Modern wire rope was invented by Wilhelm Albert, a German mining engineer, between 1831 and 1834. He developed them in order for work in the mines in the Harz Mountains. This rope replaced weaker natural fiber ropes, like hemp rope and manila rope, and weaker metal ropes, like chain rope.

Albert’s rope was constructed of four three-stranded wires. In 1840, a Scot named Robert Stirling Newall improved upon this model. A year later in the United States, American manufacturer John A. Roebling started producing wire rope, aimed at his vision of suspension bridges. From there, other interested Americans, such as Erskine Hazard and Josiah White, used wire rope in railroad and coal mining applications. They also applied their wire rope techniques to provide lift ropes for something called the Ashley Planes project, which allowed for better transportation and increased tourism in the area.

Approximately twenty-five years later, back in Germany in 1874, the engineering firm Adolf Bleichert & Co. was founded. They used wire rope to build bicable aerial tramways for mining the Ruhr Valley. Years later they built tramways for both the Wehrmacht and the German Imperial Army. Their wire rope systems spread all across Europe, and then migrated to the USA, concentrating at Trenton Iron Works in New Jersey.

Over the years, engineers and manufacturers have created materials of all kinds to make wire rope stronger. Such materials include stainless steel, plow steel, bright wire, galvanized steel, wire rope steel, electric wire, and more. Today, wire rope is a staple in most heavy industrial processes. Wherever heavy duty lifting is required, wire rope is there to facilitate.

Wire rope is strong, durable, and versatile. Even the heaviest industrial loads may be lifted with a well-made wire rope because the weight is distributed evenly among constituent strands.

There are three basic elements of which wire ropes are composed: wire filaments, strands, and cores. Manufacturers make wire rope by taking the filaments, twisting or braiding them together into strands, and then helically winding them around a core. Because of this multiple strand configuration, wire rope is also often referred to as stranded wire.

The first component, the filaments, are cold drawn rods of metal materials of varying, but relatively small diameter. The second component, the strands, can individually consist of as few as two or as many as several dozen filaments. The last component, the core, is the central element around which strands are wrapped; wire rope cores maintain a considerable amount of flexibility, while increasing strength by at least 7.5% over the strength of fiber core wire ropes.

The helical winding of the strands around the core is known as the lay. Ropes may be right hand lay, twisting strands clockwise, or they may be left hand lay, twisting strands counter-clockwise. In an ordinary lay, the individual strands are twisted in the opposite direction of the lay of the entire rope of strands to increase tension and to prevent the rope from coming unwound. Though this is most common Lang"s lay has both the strands and the rope twisted in the same direction while alternate lays, as the name suggests alternate between ordinary and Lang style lays. While alternative rope designs are available, the helical core design is often favored, as it allows a wire cable to hold a lot of weight while remaining ductile.

There are many design aspects that wire rope manufacturers consider when they are creating custom wire rope assemblies. These include: strand gauge (varies based on application strength, flexibility, and wear resistance requirements), wire rope fittings (for connecting other cables), lay, splices, and special coatings. Specially treated steel cable and plastic coated cables, for instance, are common to many application specific variations of wire rope such as push pull cable assemblies used in transferring motion between two points.

Suppliers typically identify wire cable by listing both the number of strands and the amount of wires per strand respectively, though stranded cable may alternatively be measured by their lay and length or pitch. For example, a door-retaining lanyard wire rope is identified by its 7 x 7 construction, and wire rope used for guying purposes is identified by its 1 x 19 construction. The most common types are 6 x 19, 6 x 25, 19 x 7, 7 x 7, 7 x 19, 6 x 26, and 6 x 36.

An ungalvanized steel wire rope variety. This uncoated wire rope can also be designed to resist spinning or rotating while holding a load; this is known as rotation resistant bright wire rope.

Also called a coiled wire rope, a coiled cable is a rope made from bundles of small metal wires, which are then twisted into a coil. Wire rope and cable can come in a huge variety of forms, but coiled cables specifically provide the benefits of easy storage and tidiness. Unlike other wire ropes, coiled cables do not require a spool for storage. Because it has been coiled, the cable will automatically retract into its spring-like shape when it is not in use, making it incredibly easy to handle.

A type of high strength rope, made of several individual filaments. These filaments are twisted into strands and helically wrapped around a core. One of the most common types of wire rope cable is steel cable.

Wire rope made not as one solid piece, but as a piece made up of a series of metal links. Wire rope chain is flexible and strong, but it is more prone to mechanical failure than wire rope.

Push pull cables and controls are a particular type of control cable designed for the positive and precise transmission of mechanical motion within a given system. Unlike their counterpart pull-pull cables, these wire rope assemblies offer multidirectional control. Additionally, their flexibility allows for easy routing, making them popular in a number of industrial and commercial applications.

Iron and steel are the two most common materials used in producing wire ropes. A steel wire is normally made from non-alloy carbon steel that offers a very high strength and can support extreme stretchable forces. For even more strength and durability, manufacturers can make stainless steel wire rope or galvanized steel wire rope. The latter two are good for applications like rigging and hoisting.

Technically, spiral ropes are curved or round strands with an assemblage of wires. This gathering of wires has at least one cord situated in the opposite direction of the wire in the outer layer of the rope. The most important trait of this rope is that all the wires included are round. The biggest benefit of this category of rope is that it does not allow the entrance of pollutants, water, or moisture.

Contain an assemblage of strands placed spirally around a core. Stranded rope steel wire patterns have different layers that cross each other to form an even stronger cable or rope. Stranded ropes contain one of three types of core: a fiber core, a wire strand core, or a wire rope core.

Provide an added level of security to a manufacturing production application. Wire rope slings are made from improved plow steel wire ropes that, apart from offering added security, also provide superior return loop slings. Plow steel wire ropes improve the life of a mechanism by shielding the rope at its connection points. The key objective of wire rope slings is to enhance the safety of an application while increasing its capacity and performance. Rope slings are also available in various sling termination options, such as hook type, chokers, and thimbles.

The eye in this rope sling is made using the Flemish Splice method. Just like a typical sling, a Permaloc rope sling improves safety and provides reverse strength meaning that the uprightness of the eye does not depend on the sleeves of the metal or alloy. Additionally, permaloc rope slings offer an abrasion resistance feature that makes them long lasting.

These slings have all the features that most other slings offer. However, compared to their counterparts, Permaloc bridle slings provide better load control, wire rope resistant crushing, robust hooks and links that work for a longer duration, and help save on maintenance requirements.

Manufacturers produce wire rope for many different reasons; from cranes to playground swings, wire ropes have something for everyone. Among the many applications of wire rope are hoisting, hauling, tie down, cargo control, baling, rigging, anchoring, mooring, and towing. They can also serve as fencing, guardrails, and cable railing, among other products.

Some of the industries that make use of wire rope include industrial manufacturing, construction, marine, gas and oil, mining, healthcare, consumer goods, and transportation. Others include the fitness industry, which uses plastic coated cable products in weight machines, the theater industry, which uses black powder coated cables for stage rigging, the recreation industry, which uses plastic coated cables for outdoor playground equipment, and the electronics industry, which uses miniature wire rope for many types of electronic equipment and communications devices.

Wire ropes are typically made from cold drawn steel wire, stainless steel wire, or galvanized wire. They may also be made from a wide variety of less popular metals, including aluminum, nickel alloy, bronze, copper, and titanium. However, nearly all wire ropes, including control cables, are made from strands of cold drawn carbon steel wires. Stainless steel rope and cables are subbed in for highly corrosive environments. Galvanized cables and galvanized wire rope are popular for their increased strength and durability; these qualities are important to specialized ropes like galvanized aircraft cable.

A core may be composed of metal, fiber or impregnated fiber materials depending on the intended application. Cores may also be another strand of wire called an independent wire rope core (IWRC).

Wire rope, depending on its application, is subject to many standard requirements. Among the most common of these are the standards detailed by OSHA, ASTM International, and ISO. Per your application and industry, you’ll likely have others you need to consider. To get a full list, talk to your service provider.

To determine the safety factor, which is a margin of security against risks, the first step involves knowing the type of load that the rope will be subjected to. The load must consider the shock loads and blowing wind effects. The safety factor is characterized in ratios; typical are 4:1 and 5:1. If a ratio is 5:1, then the tensile strength of a wire rope must be five times of the load it will be subjected to. In some applications, the ratios can go up to 10:1.

By weighing all these factors carefully, the wire rope that you will buy will be safe to use and last considerably. For the best advice and guidance, though, don’t go it alone! Find a great wire rope supplier that you can trust. You’ll know you’ve found the right supplier for you when you talk to one that can not only fulfill your requirements, but shows that they are excited to go the extra mile for you. For a company like this, browse the list near the top of the page.

As the cables play an integral role in the safety of many operations and structures, careful analysis of a wire rope and all of its capabilities and features is vital. Important qualities and physical specifications you must consider include wire rope diameter, breaking strength, resistance to corrosion, difficulty of flattening or crushing, bendability, and average lifespan.

Each of the aforementioned considerations should be compatible with the specific application for which the rope is intended as well as the environment in which such operations are undertaken. Temperature and corrosive environments often require specially coated wire ropes with increased durability.

When you use your industrial wire rope, the first thing to remember is to not exceed your rope’s rated load and breaking strength. If you do not stay within these parameters, you risk causing your rope to weaken or even break.

Rust, kinks, fraying and even carefully performed splicing will all have an impact on the performance of wire ropes. To maintain the integrity of your wire rope assembly, you need to inspect them regularly and clean and lubricate them as needed. In addition, you need to store them out of the wet and cold as much as possible. Also wrap them up properly, so they are not kinked.

A high-carbon steel having a tensile strength of approximately 260,000 psi that is roughly fifteen percent stronger than Plow Steel. Most commercial wires are made from IPS.

A low carbon steel wire of approximately 10,000 psi, which is pliable and capable of repeated stresses from bending around small sheaves. This grade is effective for tillers, guys and sash ropes.

The manner in which the wires are helically wound to form rope. Lay refers specifically to the direction of the helical path of the strands in a wire rope; for example, if the helix of the strands are like the threads of a right-hand screw, the lay is known as a right lay, or right-hand, but if the strands go to the left, it is a left lay, or left-hand.

A classification of wire rope according to its breaking strength. The rank of grades according to increasing breaking strengths is as follows: Iron, Traction, Mild Plow Steel, Plow Steel, Improved Steel, Extra Improved Steel.

The act of fastening a termination to a wire rope through physical deformation of the termination about the rope via a hydraulic press or hammering. The strength is one hundred percent of the wire rope rating.

A grade of rope material that has a tensile strength range of 180,000 to 190,000 psi. Traction steel has great resistance to bending fatigue with a minimum of abrasive force on sheaves and drums, which contributes to its long use in elevators, from which the steel gets its name.

It is composed of wire strands that are braided together. Wire braid is similar to stranded wire. The difference between the two is the fact that stranded wire features strands that are bundled together, rather than braided.

Essential parts of cable assemblies, wire rope assemblies and wire rope slings that assist spliced or swaged rope ends in connecting to other cables and keeping cables and rope from unraveling.

A wire rope cable assembly is a metallic rope consisting of bundles of twisted, spiraled, or bonded wires. While the terms wire rope and cable are often used interchangeably, cables are typically designated as smaller diameter wire ropes, specifically wire ropes with a diameter less than 3/8 inch. Therefore, wire rope cable assemblies are typically utilized for lighter duty applications.

Or cable assemblies, are cables which are composed of many spiraled bundles of wire. These cables are used to support hanging objects, connect objects, pull or lift objects, secure items, and much more.

Wire rope wholesalers can sell an extensive range of wire rope and wire rope accessories at a very affordable rate as well as in bulk. Many of the additional wire rope equipment that wire rope wholesalers provide include: swivel eye pulleys, eye nuts, eye bolts, slip hooks, spring hooks, heavy duty clips, clevis hooks, turnbuckle hooks, anchor shackle pins, s hooks, rigging blocks, and much more. Wire rope fittings will generally improve the versatility of the wire and also prevent fraying.

• Tensile Strengths are determined in accordance with Cordage Institute 1500.2. Test Methods for Fiber Rope. Minimum Tensile Strength (MTS) published assumes spliced eye tenninations at each end of the rope. Weights actually calculated at linear density under state preloaded (200d’J plus 4%. Diameter and circumference size published is nominal and reflects rope size after loading (10 cycles) to 50% ofMTS. See reverse side for application and safety information .

Plasma® 12 strand is the highest strength synthetic rope available. Plasma® 12 strand is manufactured from High Modulus Polyethylene (HMPE) that has been enhanced by Cortland’s patented recrystallization process. This process is especially effective in medium to large diameter ropes where strengths are over 50% higher and creep is significantly less than that of standard Spectra® 12 strand.

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. Wire rope comes in a variety of strand patterns including single layer, filler wire, seale, warrington, and combination. Wire rope strands can be laid around the core in different configurations including regular lay wire rope, lang lay wire rope, and alternate lay wire rope. There also many types of grades of wire rope, including: improved plow steel (IPS), extra improved plow steel (EIPS), and extra extra improved plow steel (EEIPS). Some types of wire rope is preferred over others due to the unique properties, including: rotation resistant wire rope, compacted strand wire rope, swaged wire rope, plastic coated wire rope, plastic impregnated (PI) wire rope.

To accommodate for heavier weights and more heavy-duty applications, industrial wire ropes are available in different designs. Some of the most important elements to consider when purchasing wire rope for sale are:

Elite Sales offers a wide range of options for wire rope. Wire rope capacity can be adjusted based on your individual applications. Here are a few options to consider:

Material.Steel grades in wide use today are improved plow steel (IPS) or extra improved plow steel (EIPS); Stainless steel grades 302/304 and 316 are most common.

Industrial wire rope or cables are comprised of three key elements which all serve to support the rope’s strength and durability. It is important to understand the purpose of each of these components and the options available.

Wires: The most basic element of the wire rope are the individual wires used to form the cable. The thicker the diameter of the wire, the stronger it is, while thinner wires are more flexible.

Strands: A combination of multiple wires that are woven together form a strand. These strands are wrapped tightly together to maximize their strength and prevent uneven wear or breakage.

Fiber Core(FC) which can be made of natural or synthetic fibers that gives the wire rope some elasticity. However, it is not extremely strong nor is it optimal for high heat.

Wire Strand Core (WSC) consists of a singular wire strand which the other wires are wrapped around. This provides added stability while providing flexibility in the wire rope.

The standard type of steel wire rope for oil and gas industry is not the same as that of the letter mark in our national wire rope standard; the current national standard for steel wire rope is mainly the general purpose steel wire rope GB/T20118-2006 and the important use wire rope GB8918-2006.

According to the selection and maintenance of steel wire ropes used in SY/T6666-2006 oil and gas industry, the majority of English letters represent the following meanings:

The 6 x 19 classification of wire ropes includes standard 6 strand, round strand ropes with 16 through 26 wires per strand. The 6 x 36 classification of wire ropes includes standard 6 strand, round strand ropes with 27 through 49 wires per strand. Although their operating characteristics vary, all have the same weight per foot and the same nominal strength, size for size.

While the 6 x 19 ropes give primary emphasis to abrasion resistance in varying degrees, the 6 x 36 ropes are important for their fatigue resistance. This fatigue resistance is made possible by the greater number of small wires per strand.

Although there are exceptions for special applications, the constructions in 6 x 36 classification are primarily designed to be the most efficient for each rope diameter. As the rope size increases, for instance, a large number of wires can be used to achieve required fatigue resistance, and still those wires will be large enough to offer adequate resistance to abrasion.

In this construction, each strand has nine outer wires over nine smaller inner wires over one large center wire. A comparison of cross-sections shows that these outside wires are larger than those of the 6 x 25FW or 6 x 26WS. Therefore, its resistance to abrasion is increased, but its fatigue resistance is decreased. This is a good rope to withstand abrasion or crushing on the drum.

To most wire rope users, 6 x 19 means 6 x 25 filler wire. It is the most common rope in the 6 x 19 classification. This rope has a good balance between both abrasion resistance and fatigue resistance in relation to other ropes.

This construction has better resistance to abrasion than a 6 x 25FW. It also features a compact construction with solid support for the wires; hence, it has a high resistance to crushing. Its number and relative size of the inner wires add to the stability of the strand and gives it a fatigue resistance comparable to a 6 x 25FW.

A standard 6 x 26WS construction provides the best rope for a wide range of applications. In general, we recommend the use of a 6 x 26WS in any application where a 6 x 25FW is used.

In most rope sizes, only one 6 x 36 classification rope is made. These constructions were selected to provide fatigue resistance without having wires that are too small.

The greater number of wires in the 6 x 36 classification makes these ropes more susceptible to crushing. This can be minimized, however, by specifying an Independent Wire Rope Core (IWRC) and by using well-designed sheaves, grooved drums and proper operating techniques.

Rotation-resistant ropes can frequently provide the best and most economical service in specific applications when you choose, handle and use them properly.

Contra-helically laid, rotation-resistant ropes are different from standard ropes because they"re designed to reduce rope torque. Modes of failure and wear for rotation-resistant ropes can differ from those for standard rope constructions. The very nature of these ropes requires special handling, selection and usage not encountered with standard constructions. They are susceptible to kinking, crushing and unbalancing in the form of "core pops" and "birdcages" Use extreme care to avoid operational practices that can possibly lead to these conditions.

Rotation-resistant ropes should not be used with swivels that allow rope rotation -- or in single part lifts where the load can rotate. Rotation will cause a reduction in strength, unequal loading in the rope and possible rope unbalance. If any significant change in diameter is found in a short length of a rotation-resistant rope, the rope needs to be replaced.

These ropes should be replaced when you see two randomly distributed crown wire breaks in six rope diameters -- or four randomly distributed crown wire breaks in 30 rope diameters.

Because rotation-resistant ropes are special, there are separate design, maintenance, inspection and removal criteria established for them by applicable industry regulations and standards.

In an application where a single-part hoist rope is used to lift a free load -- or where rotation-resistant properties are essential for rope performance -- the 19 x 7 can be used. Its rotation-resistant characteristic is achieved by laying six strands around a core strand in one direction, then laying 12 strands around the first operation in the opposite direction. Thus, when the rope is in tension, opposing rotational forces are created between the inner and outer layers.

In addition, frequent and regular inspection for broken wires is critical when using this rope. Due to its design, the 19 x 7 construction has a relatively low reserve strength. This can result in short service life between the point in time when the broken wire removal criteria are met and when actual rope failure occurs.

In a multi-part wire rope system where the blocks have a tendency to twist -- or for a single-part hoist line that doesn"t require the degree of rotation-resistant properties found in a 19 x 7 rope -- the 8 x 25 Resistwist rope has found successful application. The rotation-resistant characteristic is achieved by laying the eight outer strands around an independent wire rope core so these strands are in the opposite direction to the lay of the core. Thus, when the rope is in tension, opposing rotational forces are created between the core and the outer strands.

Though not as rotation-resistant, the 8 x 25 Rotation Resistant rope is more stable than a 19 x 7 rope. It also has increased resistance to bending fatigue and crushing. This is achieved through the use of eight-strand construction with an independent wire rope core.

Like any application where an installation"s rope type is changed, the 8 x 25 Rotation Resistant rope should be substituted only after carefully comparing specifications and strength requirements.