wire rope break quotation

Like all industrial equipment, aircraft cables and wire ropes wear while in service, and will require replacement. Though the cycle life of each cable varies based on construction and application, factors such as load and pulley condition can actually reduce this lifespan by triggering wire breaks. Not all wire breaks look the same, and understanding these differences can help detect issues in your system before they damage additional cables, or put human lives in danger. Here is a quick guide to help you understand where wire breaks occur (crowns vs. valleys), and three common examples of wire breaks (tension, fatigue, and abrasion).

Wire breaks typically occur in two different locations on the outside of wire rope or aircraft cable. The first location is on the crowns of the strands, which are the highest points with the most surface area exposure. The second location is the valleys, or the spaces between the strands. Though crown breaks typically result from normal wear and tear, valley breaks are more suspicious and may indicate issues with the pulley system or wire rope itself.

Wires that have been worn to a knife-edge thinness are characteristic of abrasion breaks. Abrasion can occur from a number of different sources, but sheaves are the most common. Remember to check sheaves for signs of wear, damage, or deformity and replace as necessary.

If you notice one end of a broken wire is cupped, and the other end resembles a cone, your wire rope likely experienced a tension break. Tension breaks result from excessive loading, causing the wires to stretch beyond their limits until they snap. Once one wire break appears, others will continue to occur if the cable is not addressed.

Fatigue damage is usually represented by zig-zag breaks with square ends. Like abrasion breaks, fatigue breaks can be triggered by a broad range of factors, including incorrect pulley size and excessive vibration. Check for worn pulleys and slack in the system to prevent issues from exacerbating.

Once you have replaced your damaged pulleys, or removed sharp obstructions in your system, begin your quote for brand new wire rope at https://strandcore.com/contact/. Our wire rope craftsmen can help you select the ideal wire rope for your application, and oftentimes provide a better solution for your existing setup. Browse our selection ofwire rope and aircraft cableonline, and do not hesitate to contact our sales team at sales@sanlo.com if you have any questions.

Understand that most of the people out from the industry always face the problem of having no idea with the terms of wire rope when receiving quotation. In this update, we will explain in the most simple way and hopefully it is applicable to anyone.

6X36 = Construction of wire rope (There are quite a lot different constructions available for different application for example like, 6X25, 6X29, 6X31, 4X39, 19X7, 8X26 etc.)

RHOL = Right hand ordinary lay, it is the wire lay direction and very important to select the right direction of wire when dealing with multi-reeving, crane and hoist application.

EIPS (1960) = Extra improved plow steel and 1960 stands for the tensile strength 1960N/mm2. The figure is telling you the grade of wire rope, lower or higher tensile strength will result in different breaking strength.

UNGALVD = Ungalvanized, the surface finishing of wire rope. Galvanized and Ungalvanized are the basic surface finishing selection with different grade of lubrication.

MECH SPLICED = Mechanical splicing is the process of using hydraulic pressure to press the aluminum sleeve or metal sleeve and a loop is formed. This phrase is always telling you the terminal of both end wire rope. It can be plain, socketed, fuse tapered or eye formed.

Wire rope could have a lot of variation upon the application which I will cover in the next update. The essay above is good enough to tell the basic and hope it helps for procurement department while dealing with steel wire rope. Last but not least, selecting the right wire rope is crucial to your company"s long term expenditure and safety purposes. Do not take the risk because of cheap.

Rope strength is a misunderstood metric. One boater will talk about tensile strength, while the other will talk about working load. Both of these are important measurements, and it’s worth learning how to measure and understand them. Each of these measurements has different uses, and here we’re going to give a brief overview of what’s what. Here’s all you need to know about rope strength.

Each type of line, natural fiber, synthetic and wire rope, have different breaking strengths and safe working loads. Natural breaking strength of manila line is the standard against which other lines are compared. Synthetic lines have been assigned “comparison factors” against which they are compared to manila line. The basic breaking strength factor for manila line is found by multiplying the square of the circumference of the line by 900 lbs.

As an example, if you had a piece of ½” manila line and wanted to find the breaking strength, you would first calculate the circumference. (.5 X 3.14 = 1.57) Then using the formula above:

To calculate the breaking strength of synthetic lines you need to add one more factor. As mentioned above, a comparison factor has been developed to compare the breaking strength of synthetics over manila. Since synthetics are stronger than manila an additional multiplication step is added to the formula above.

Using the example above, letÂ’s find the breaking strength of a piece of ½” nylon line. First, convert the diameter to the circumference as we did above and then write the formula including the extra comparison factor step.

Knots and splices will reduce the breaking strength of a line by as much as 50 to 60 percent. The weakest point in the line is the knot or slice. However, a splice is stronger than a knot.

Just being able to calculate breaking strength doesn’t give one a safety margin. The breaking strength formula was developed on the average breaking strength of a new line under laboratory conditions. Without straining the line until it parts, you don’t know if that particular piece of line was above average or below average. For more information, we have discussed the safe working load of ropes made of different materials in this article here.

It’s very important to understand the fundamental differences between the tensile strength of a rope, and a rope’s working load. Both terms refer to rope strength but they’re not the same measurement.

A rope’s tensile strength is the measure of a brand-new rope’s breaking point tested under strict laboratory-controlled conditions. These tests are done by incrementally increasing the load that a rope is expected to carry, until the rope breaks. Rather than adding weight to a line, the test is performed by wrapping the rope around two capstans that slowly turn the rope, adding increasing tension until the rope fails. This test will be repeated on numerous ropes, and an average will be taken. Note that all of these tests will use the ASTM test method D-6268.

The average number will be quoted as the rope’s tensile strength. However, a manufacturer may also test a rope’s minimum tensile strength. This number is often used instead. A rope’s minimum tensile strength is calculated in the same way, but it takes the average strength rating and reduces it by 20%.

A rope’s working load is a different measurement altogether. It’s determined by taking the tensile strength rating and dividing it accordingly, making a figure that’s more in-line with an appropriate maximum load, taking factors such as construction, weave, and rope longevity into the mix as well. A large number of variables will determine the maximum working load of a rope, including the age and condition of the rope too. It’s a complicated equation (as demonstrated above) and if math isn’t your strong point, it’s best left to professionals.

However, if you want to make an educated guess at the recommended working load of a rope, it usually falls between 15% and 25% of the line’s tensile strength rating. It’s a lotlower than you’d think. There are some exceptions, and different construction methods yield different results. For example, a Nylon rope braided with certain fibers may have a stronger working load than a rope twisted out of natural fibers.

For safety purposes, always refer to the information issued by your rope’s manufacturer, and pay close attention to the working load and don’t exceed it. Safety first! Always.

If you’re a regular sailor, climber, or arborist, or just have a keen interest in knot-tying, be warned! Every knot that you tie will reduce your rope’s overall tensile strength. Some knots aren’t particularly damaging, while others can be devastating. A good rule of thumb is to accept the fact that a tied knot will reduce your rope’s tensile strength by around 50%. That’s an extreme figure, sure, but when it comes to hauling critical loads, why take chances?

Knots are unavoidable: they’re useful, practical, and strong. Splices are the same. They both degrade a rope’s strength. They do this because a slight distortion of a rope will cause certain parts of the rope (namely the outer strands) to carry more weight than others (the inner strand). In some cases, the outer strands end up carrying all the weight while the inner strands carry none of it! This isn’t ideal, as you can imagine.

Some knots cause certain fibers to become compressed, and others stretched. When combined together, all of these issues can have a substantial effect on a rope’s ability to carry loads.

Naturally, it’s not always as drastic as strength loss of 50% or more. Some knots aren’t that damaging, some loads aren’t significant enough to cause stress, and some rope materials, such as polypropylene, Dyneema, and other modern fibers, are more resilient than others. Just keep in mind that any knots or splices will reduce your rope’s operations life span. And that’s before we talk about other factors such as the weather or your rope care regime…

Use the "rag-and-visual" method to check for external damage. Grab the rope lightly and with a rag or cotton cloth, move the rag slowly along the wire. Broken wires will often "porcupine" (stick out) and these broken wires will snag on the rag. If the cloth catches, stop and visually assess the rope. It is also important to visually inspect the wire (without a rag). Some wire breaks will not porcupine.

Measure the rope diameter. Compare the rope diameter measurements with the original diameter. If the measurements are different, this change indicates external and/or internal rope damage.

Visually check for abrasions, corrosion, pitting, and lubrication inside rope. Insert a marlin spike beneath two strands and rotate to lift strands and open rope.

Corrosion from lack of lubrication and exposure to heat or moisture (e.g., wire rope shows signs of pitting). A fibre core rope will dry out and break at temperatures above 120°C (250°F).

Kinks from improper installation of new rope, sudden release of a load or knots made to shorten a rope. A kink cannot be removed without creating a weak section. Discarding kinked rope is best.

Safety should be the top concern of anyone employed in rigging. When working a job where so many lives could be cut short due to carelessness, there is no excuse for laziness or distraction. Rigs should be inspected thoroughly for any potential areas of breakage. It is important for employees to gain a fluency in the causes of wire rope damage and failures so they can spot areas of weakness and fix them before they grow into a dangerous problem.

Corrosion issues in wire ropes are one of the most difficult causes of wire rope damage and failures to identify, which is why it is one of the most dangerous. Wire rope failures due to corrosion are typically the result of poor lubrication. You can measure some amount of the lubrication by looking at the pitted surface of every individual rope, but this tells us little of the damage done to the core. Since it is difficult to identify the full spectrum of corrosion, this break stands apart as mysterious and deadly.

Abrasion-caused failure occurs when the wire rope has been damaged by irregular contact with hoist sheaves and drums or when it awkwardly rubs against an object such as shelving or a crane girder. It is also often caused by poorly grooved drums and sheaves. You know the wire ropes have experienced abrasions when the wire ends are worn thin.

When hoist ropes go through repetitive bending over sheaves, cracks will eventually develop in the individual wires. Sections of the wire that move over the sheaves develop the worst fatigue. The damage can often be seen by the naked eye. Whenever one broken wire appears due to fatigue, more will follow. Since these issues are essentially the result of wear and tear on the rope wire, they are considered a normal part of operating a crane.

At Carl Stahl Sava Industries, our steel mechanical cable choices include 304 and 316 stainless steel and galvanized steel cable. Sava is both a wire rope supplier and a wire rope manufacturer that is able to work withexotic steel alternatives upon request, both stainless steel and galvanized steel mechanical cable offer distinct benefits, depending upon the application. Read on to learn the differences between galvanized vs. stainless steel wire ropeand determine which custom wire rope will better serve your application requirements.

One of the greatest benefits of stainless steel wire rope is that it is suitable for nearly any application. While it may have a slightly higher cost than galvanized steel cable, stainless steel cable provides customers with greater ROI and maintains its high-strength qualities over its lifespan under most conditions. While not as strong as tungsten or tolerant of excessive temperatures, stainless steel mechanical wire rope is an incredibly effective cable construction material.

Stainless steel has high corrosion resistance due to it being treated with chromium. This additional element makes stainless steel suitable for use in moist environments, even when harmful salty conditions are present. Specifically in marine environments, for instance, stainless steel wire rope can be used for years without corroding. And in the medical devices field, stainless steel is commonly the metal of choice for many medical device instruments like endoscopes because of its high sanitization level and durability over many cycles makes it ideal.

Galvanized steel is steel that has been dipped in a zinc coating, which gives it good corrosion-resistant qualities. But even with the addition of zinc, galvanized wire rope’s strength is weaker than stainless steel because of the presence of chromium, making the cable stronger and more tolerant of corrosive elements like saltwater. Galvanized cable will rust and corrode if salty wet conditions are present. And like stainless steel, galvanized steel cable ends will also weld together if they make contact with one another.

Galvanized steel cable is often found in industrial applications, since items may brush up against the wire rope in the field, which again, are environmental conditions that galvanized steel tolerates quite well over time. For this and other reasons, Galvanized steel wire rope works exceptionally well in aerospace applications.

Stainless steel wire rope is a cost-effective solution that works across a range of applications, is impervious to salty wetness and is stronger than galvanized steel cable. But galvanized steel wire rope is corrosion-resistant, except when salt is present and tolerates contact with itself far better than stainless steel cable.

It"s important to remember that since each application has unique needs, these comparisons are general guidelines. Contact Sava today to discuss your project, so we can help you determine whether a stainless steel wire rope or galvanized steel wire rope is best for your cable manufacturing needs.

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.

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:

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.