steel wire rope breaking strength quotation

METRIC WIRE ROPES- 6 x 36 wire rope is a more flexible cable wire than 6 x 19 wire rope since it has a higher number of wires per strand. Some of the most common uses are winch lines, choker and boom lines, and works well in marine environments.

* EIPS (Extra Improved Plowed Steel) wire rope has roughly 10% more strength than regular IPS. Independent wire rope core ( IWRC ) provides added strength, reduces the amount of stretch. IWRC wire rope also is resistance to heat and provides extra corrosion resistance over a typical bright wire finish.

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…

It is because of the versatility of wire rope that engineers must be deeply educated on tensile strength, as well as the impact that wire rope diameter and strand constructions can have on tensile strength, along with other critical characteristics such as cycle count and flexibility.

All wire ropes are tested for breaking strength. Motion cables have a minimum breaking strength requirement, which is determined by the material, diameter and construction of the wire rope. At Carl Stahl Sava Industries, wire rope is tested on tensile strength equipment. Either or both the wire rope itself can be tested against the minimum load requirement, or the fittings swaged to the wire rope can be similarly tested for their holding strength on the cable.

To ensure wire rope stays within its specified tensile limits, engineers will derate the minimum cable tensile strength by a safety factor. This is how engineers arrive at what is known as the Working Load Limit or WLL. The WLL safety factor of each cable being tested is application specific, but often times a factor of 3 to 5 is utilized. Divide the minimum tensile strength by the safety factor to calculate the safe working load limit for a specific cable.

Steel cables are made more durable in part due to a manufacturing process known as cold working or cold forming, where the material is shaped below its recrystallization temperature. Cold worked steel distorts the steel’s crystal grains in the flow of the metal, resulting in hardening of the material, thus strengthening it. Due to steel’s natural strength, combined with its well-known resistance to corrosion, engineers turn to steel cables for applications where exposure to harsh environments does not compromise wire rope integrity.

At Sava, we ensure that our steel cables are manufactured using 304, 305 and 316 stainless steel, all of which significantly reduce the risk of corrosion, apart from those exposed to seawater. The general rule of thumb, however, is that engineers should never exceed the manufacturer"s limitations when using steel cables.

Although commonly mistaken for stranded cable, braided cable refers to the braided wrapping or insulation found in conductive cables, such as those transmitting power or data. This braided “jacket” insulates and strengthens the conductive, data or electric cable, making it more tolerant to time in the field, along with the twisting, turning and rolling to which braided cable is commonly exposed. Sava does not manufacture braided cable or other conductive cable, like coaxial and network cable, as none of these cables, commonly braided in nature, actuate motion.

Interestingly, even Google machine learning algorithms struggle to understand the differences between motion cable, such as steel wire rope or tungsten mechanical cable, and cables that transmit electricity or information. When a searcher uses Google or other common search engines like Bing or Yahoo! to find steel cable manufacturers like Sava, or for that matter, a maker of braided cable, the search engine confuses the two and often serves the wrong cable to the searcher.

Wire rope manufacturers offer a wide range of what is known as “cable constructions,” which characterizes the number of individual wires used to stranded the wire rope. Consequently, most wire rope comprises a center or “core” wire, that is then wrapped in more wires, thus completing the stand’s construction. In the case of a 1x7 steel cable construction, the core wire represents wire #1, wrapped in six additional wires. Hence 1x7 steel cable.

In many cases, that same 1x7 steel cable is then used as the core in the manufacture of larger, stronger and more durable steel cable. For instance, 7x19 steel cable strand comprises the original seven wires, or 1x7 strand, and is wrapped in 12 more wires, thus making a 7x19 construction. Said another way, the 7x19 wire rope consists of the original 1x7 strand, plus 12 additional wires, making for a total of 19 wires.

Less seldom are wire rope constructions that do not include a core wire. In these cases, take 3x7 cable construction for instance, three, 1x7 stranded wire ropes are wrapped around one another, forming a triangular-shaped wire rope construction.

Sava offers a wide array of cable constructions, manufactured in stainless steel, galvanized steel, coated or bare, as well as tungsten cables and those made from other more exotic materials. For a quotation on any product on our catalog or further assistance, get in touch with our team of engineers. At Sava, we offer the highest quality materials at affordable rates. Contact us today to get started.

Regular Lay RopeThe most standard, and accepted for a wide range of applications. The direction of the individual wires is opposite to the direction of the strands. Because of this, the rope is less likely to untwist, and therefore is easier to handle than lang lay rope. This rope is also less subject to crushing.

The individual wires that form strands are most commonly available in high-carbon steel, generally supplied in an uncoated, or "bright" finish. Zinc coated, or "Galvanized" rope is available in some sizes and carries a nominal strength of 10% below that of a bright rope. On special request, wire rope can be drawn-galvanized, offering the same nominal strength as a bright rope.

Wires are laid geometrically to form strands, each composed of two or more wires. Breaking these strand configurations into several classifications is the basis for identifying wire rope.

The core is the supporting member of the rope, made of steel. A steel center rope yields a higher strength along with the ability to resist crushing Steel cores are required when the environment exceeds 180°(F)

Type 304 stainless steel is the standard alloy for use in wire rope and cable. It has about the same strength as galvanized rope or cable but is much more corrosion resistant. It can be used in most industrial atmospheres and has acceptable corrosion resistance when used in marine and salt water.

Type 316 stainless steel is the standard high corrosion resistant steel for rope and cable. It is resistant to many chemicals in the pulp and paper, photographic, food processing and textile industries. It has the best pitting resistance in marine and salt water and can be used in temperatures up to 480ºC (900ºF).

We understand that there are many factors that go into choosing the correct sling, wire rope, rigging hardware or lifting device for a lift! Let our sales team help!