secure wire rope made in china

Q2. What’s safety factor does your product use?A2: General, use a 5 to 1 or 3 to 1 safety factor when we design it. eg: breaking load is （1000 N）100 kgs, safety factor is 5:1 （200 N), Breaking strength should never be considered the ropes working load.Q3. I would get a flexible cable assembly first to testing the performance, how do I choose?A3: The same diameter of steel wire cable ,the 7X19 construction is more flexible than the 7X7 construction. eg:1/16’’7X19 steel wire rope more flexible than 1/16’’7X7Q4. Which material should I choose?A4: Stainless steel cable has better corrosion resistance, but more expensive and slightly less tensile strength than galvanized wire cable. If it is used for general industry, galvanized steel is OK, as for marine environment, stainless steel wire cable will be recommended, It depends on you application.Q5. What’s the lead time of my order?A5: Normally,20 working days.It is largely depending on the amount of your order. If you are in urgent need of it, our team will try our best to meet your requirements,so if you have any other queries, Feel free to contact us:-) We are here ready to help!

Established in 2005, Jiangsu Safety Steel Wire Rope Co., Ltd. is a professional steel wire rope manufacturer and exporter with a profound experience. The company is located in Wuxi, Jiangsu, China covering an area of 57,108.70 square meters. They have a total annual production of steel wire rope is 25000 to 30000 tons and a registered capital 13 million U.S. dollars. Jiangsu Safety Steel Wire Rope Co., Ltd. has plenty of high-quality products to offer.Toho-Rongkee

Chongqing Toho-Rongkee Electronic and Machinery Co., Ltd is one of the best wire rope manufacturers in China that follows ISO 9001:2008, TUV, CE, SGS qualification standard on every production method and fabricated. Also offer a wide range of lifting tools, equipment, and various riggings that meet your standards. Employs over 1000 skilled workers and staff in 7 advanced factories in China.Tianli Stainless Steel Products Co., Ltd

Tianli Stainless Steel Products Co., Ltd is specialized in manufacturing steel wire ropes headquarters in Dainan Town, Jiangsu Province China. Currently having more than 50 existing employees in over 6600 square meters factory area. They can provide excellent advice and assistance to ensure you obtain the right products at the lowest cost.Guizhou Wire Rope Incorporated Company

With more than 40 years of manufacturing and technique experience, you can totally rely on Guizhou Wire Rope Incorporated Company, they have excellent production lines, modern production techniques, and excellent quality control systems. All products such as steel wire, pre-stressed wire rope, PVC coated wire rope, etc. are not only famous with excellent quality but in reasonable prices and considerate services in China. This company also receives good popularity in the overseas market.Nantong Jiaan Metal Material Co., Ltd.

Established in 2013, Jiaan Metal Material is one of the respected manufacturers of steel wire rope located in Nantong, Jiangsu, China. All the production methods, from raw material smelting, heat treatment, wire drawing, and rope twisting to physical and chemical performance examining, are under strict and scientific control based on ISO 9001 certification standard.Nantong Lili hardware products Co., Ltd.

Started in 1998, Nantong Lili hardware products Co., Ltd. continually improving and striving to provide high-grade wire rope to customers worldwide. ISO9001:2008, ISO14001:2004 certified company located in Jiangsu, China. They mainly engaged in producing steel wire rope, stainless steel wire, steel strip, stainless steel strip, spring steel strip, spring steel wire, carbon steel wire, and more.Nantong New Jianghai Internation Trade Co., Ltd.

Set up in the year 2016, Nantong New Jianghai Internation Trade Co., Ltd is an expert wire rope provider situated in Nantong, China. Owns advanced technologies and machinery to manufacture a high-class and comprehensive quality solution. They have more than 70 professional employees working and improving products according to ISO9001:2015 authentication.Jiangsu Zhongying Steel Cable Co., Ltd.

Established in 2004, Zhongying Steel Cable is one of the leading manufacturers and reputable provider of steel wire ropes situated in Nantong, Jiangsu, China. Their factory has 80, 000 square meters and the building area is about to 65,000 square meters. Workshops are equipped with advanced producing equipment and comprehensive testing facilities that’s why the partnership with them will bring business satisfaction for you.Qingdao Haito Rigging Hardware Co., Ltd

A large enterprise located in Qingdao, Shandong, China, which engaged in manufacturing rigging hardware such as steel wire rope accessories, wire rope clips, load binder, chain, wire rope, and more. They have an abundant supply of superior quality products. Founded in 2009, Haito Rigging Hardware continuously developed and improving products supported by good experience and professional employees.Gustav Wolf

With over 130 years of experience and development, Gustav Wolf is a leading superior steel wire and steel wire ropes manufacturer associated with quality and safety. Produced products according to ISO9001:2015, ISO14001:2015 certification which can meet your requirements and demands. Employs over 115 hardworking workers and staff who aim to serve customers with honesty, loyalty, and perseverance.Jiangsu Xiangchuan Rope Technology Co., Ltd.

Specialized in manufacturing high-standard wire rope, Xiangchuan Rope Technology is a dedicated supplier and manufacturer with vast experience in the field. Own a modern facility with an area of about 38, 000 square meters and employs 138 staff members and workers. Their advanced production equipment, technical know-how, skilled workers guarantee that in Xiangchuan Rope Technology you have a reliable partner.JULI SLING CO., LTD.

For more than 33 years of experience in creating comprehensive products such as wire rope, JULI SLING earned a good reputation in the steel industry appreciated by foreign and domestics customers. JULI is recognized as a pioneer in China’s lifting and rigging industry, the standard makers in rigging field, the advocate of worldwide rigging civilization. Partnership with this company will skyrocket your business project.Nantong Julong Metal Products Co., Ltd

Nantong Julong Metal Products Co., Ltd is a large private enterprise founded in 2009 that specialized in producing any types of wire rope, headquarters in Jiangsu, China. Get 100% ideal products, at a cost-effective price here in Julong Metal. Be one of their satisfied customers such as in Europe, Africa, North America, South America, Asia, the Middle East, etc.YunFeng Steel Wire Rope Products Ltd.

Located in Jiangsu province, China, YunFeng Steel Wire Rope is a professional manufacturer of all kinds of wire rope offer in excellent quality and reasonable price to customers. They can meet customers’ demands and requirements by manufacturing all kinds of products with international standards.Sinounion Industries

Founded in 1999, Sinounion Industries is a professional Steel Wire Rope manufacturer in China. Also offer Rigging Hardware, Lifting Equipment, and various Forging & Casting products. All products are manufactured according to ISO9001, ISO14001, CE, and GS standards. The company owns a wide factory area in Qingdao, Shandong province with about 35000 square meters.Ningbo BST Metal Products Co., Ltd.

Established in 2002, BST Metal Products is one of the largest and reputable steel wire rope manufacturers in China with an area of 78,000 square meters factory workshop. Backed up by more than 350 professional people & technical engineers who have a vast experience in the field, BST Metal Products ensure great and fast production exceed the national and international guidelines.Jiangsu Yasheng Metal Products Co., Ltd.

As an ISO9001:2015, ISO/TS16949:2009, ISO9001: 2000 certified company, Jiangsu Yasheng Metal Products Co., Ltd. devoted itself to producing excellent products at a favorable cost. If you`re looking for a wire rope manufacturer, then Yasheng Metal Products is the best choice! Get 100% quality products prepared by solid technical strength and professional service team.Chongqing Geyo Machinery corporation

Geyo Machinery corporation a reliable manufacturing company that focuses on research, production, sales, and service of high-quality products. Mainly engaged in manufacturing wire rope, wire rope slings, tamping rammer, power trowel, scarifying machine, etc. They have their own advanced production facilities, expert technical team, and a professional quality control team.SHANGHAIMETAL

Started in the year 1980, SHANGHAIMETAL is a premier wire rope provider. Together with a team of experts, innovative machinery, and dedicated workers, they guarantee absolute customer satisfaction. Shanghai Metal is always passionate about working and supplying excellent services to clients throughout the world. All their products are manufactured with high-quality at a reasonable cost.Huazhuo HD Machinery

Established in 1958, Qingdao Huazhuo HD Machinery Co., Ltd. is a trusted wire rope manufacturer with a profound experience, strong workmanship, and professional service team that ensures the best product at best price offer to clients around the world. A leading supplier of high-standard wire rope, rigging hardware, marine hardware, chain, lifting tools, and other high-grade metal products.

Wire ropes can be seen everywhere around us, they are made of strands or bundles of individual wires constructed around an independent core, suitable for construction, industrial, fitness, commercial, architectural, agricultural, and marine rigging applications.

Wire rod is made from high carbon steel wires(0.35 to 0.85 percent carbon) in a hot rolling process of a required diameter, usually from 5.5mm to 8 mm.

Wire rod is drawn to the required diameter by the 1st drawing machine after descaling dust and rust, adding mechanical properties suitable for application.

Positioning the wires different or the same size lay in multiple layers and same direction, or cross lay and diameter is maintained by one-third of the rope size.

So in theory, it is very simple to manufacture wire ropes. However there are many more details that must be closely monitored and controlled, and this requires time and experienced personnel since it is a super complicated project you cannot imagine.

Wire rope clips are widely used for making end terminations. Clips are available in two basic designs; the U-Bolt and fist grip. The efficiency of both types is the same.

When using U-Bolt clips, extreme care must be exercised to make certain that they are attached correctly; Incorrect installation can reduce the working load limit by 40%. Below are general guidelines for installing wire rope clips.

The saddle shall be placed on the live end of the wire rope, with the U-bolt on the dead-end side—Remember the well-known saying: “Never saddle a dead horse.” Use at least two or three wire rope clips to secure the ends properly to the length of the rope, and tighten nuts evenly one by one until reaching the recommended torque.

Step 1. Turn back a specified amount of rope from the thimble or loop. The first clip must be placed one bridge width from the turned back rope tailor dead end of the rope, Apply U-Bolt over dead end of wire rope – live end rests in the saddle (Never saddle a dead horse!) Tighten nuts evenly, alternate from one nut to the other until reaching the recommended torque.

Step 3. When three or more clips are required, space additional clips equally between the first two – take up rope slack – tighten nuts on each U-Bolt evenly, alternating from one nut to the other until reaching recommended torque.

In accordance with good rigging and maintenance practices, the wire rope end termination should be inspected periodically for wear, abuse, and general adequacy. Periodically re-tightening of the nuts must be done at 10.000 cycles (heavy usage), 20.000 e.g. every 3 months, 6 months, annually.

Malleable clips are to be used for making eye termination assemblies only with the right regular lay wire rope and only for light-duty uses with small applied loads, such as handrails, fencing, guard rails, etc.

If you have any wire rope clips questions, you can contact us by email at info@hilifting.com. We will be glad to share with you more useful information.

CIVMATS produces high quality stainless steel wire rope. Our annual production capacity is roughly 8000 tons, among which stainless steel wire rope amounts to 400 tons per month. The tolerance of our stainless steel wire rope can be as small as ±0.01mm. CIVMATS produces strictly according to ISO9001:2000. Every product delivered from CIVMATS is a reputation warranty.

Wire rope can be divided into multi-strand wire rope and single-strand wire rope. It is structured with at least two layers of steel wire or a plurality of strands spirally wound around a center or a core. Stainless steel wire rope refers to a steel wire rope made of stainless steel. In dynamic systems, stainless steel wire ropes are widely applied in the lifting of cranes and elevators, the transmission of mechanical power, the control of automobile cockpit poles and the operation of aircraft control systems, etc. In static systems, stainless steel wire ropes are also employed in various industries such as the stability of the sling bridge"s pulling support tower and the design of new railings.

Stainless steel wire rope features high temperature resistance, good fatigue resistance, excellent breaking force, long service life and durability. It is widely used in coal, petroleum, metallurgy, chemical industry, shipbuilding, bridge, electric power, rubber, military, tourism, water conservancy and light industry. The products can be produced according to ISO, BS, DIN, JIS, ABS, LR and other international and foreign advanced standards

In CIVMATS, all of our stainless steel wire ropes are packaged as per international standard to prevent any possible damage or loss. They are neatly wrapped in accurate length with securely tied rope ends. For enhanced customer experience, we also provide dedicated package as per your special requirements.

Our main grades for stainless steel wire rope are 304 and 316. We can also customize stainless steel wire rope as per your specified grades and sizes for your reference.

1. Point contact: The adjacent stainless steel wires contact in the form of point in the strands. The diameters of all the stainless steel wires, excluding the central wire are equal, and the strands are formed by layering.

2. Line contact: There is a linear contact between the adjacent layers of stainless steel wire in the strand, and the strands are made of stainless steel wires of different diameters in one process.

4. Point and line contact: There are two kinds of contact forms between the adjacent layers of stainless steel wires in the strand. The strands are made of wires of different diameters.

1. In the equipment reform of chemical, fertilizer, chemical fiber and other industries, stainless steel wire rope was used for the deployment of the updated equipment.

2. Stainless steel wire ropes are used in the applications of popular stainless steel welding rods and a considerable number of stainless steel components, springs, connecting parts, etc.,

5. Stainless steel wire ropes are also extensively used in railway electrification, decoration industry, rigging industry, fishing gear industry, automobile and motorcycle industry and other industries.

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.

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,

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,

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:

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

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).

Rotation rope and non-rotation rope or rotation resistant rope. Round strand rope, compacted rope, swaged rope. Wire rope with fiber core, wire rope with IWRC(Independent Wire Rope Core). Galvanized wire rope, ungalvanized wire rope or bright wire rope. Wire rope with plastic insert, Wire rope without plastic insert. Wire rope covered with plastic.

As one of the most professional wire rope clip manufacturers and suppliers in China, we"re featured by quality products and good service. Please rest assured to wholesale customized wire rope clip at competitive price from our factory. Din 1480 Turnbuckles with Stub Ends, Auto Accessories, Din 1480 Eye/Eye

As specialist for manufacturing quality steel wire ropes over 20 years, our company can supply strong, durable and reliable ropes that capable to minimize your downtime and maximize cost effectiveness. Decades of experience we owned make us know clearly the work you do and capable to provide professional guidance.

We select the best steel or stainless steel as raw material for wire rope manufacturing. Our products are manufactured under strict quality managements and test before they leave the factory.

Our engineers can provide professional advice about picking up optimal steel wire ropes for their application, installation guidance to ensure maximum return in their wire rope system.

If you are going to pick up steel wire ropes that suit your project perfectly, you must have an ideal about the construction about them. Our company can supply bright wire rope, galvanized wire rope, stainless steel wire rope, compacted wire rope, rotation resistant wire ropes, mining wire rope, elevator wire rope, crane wire rope and gas & oilfield wire ropes. Here are some details to solve the problem that may puzzle you whether you are browsing the web or picking up steel wire ropes.

Bright steel wire ropes mean no surface treatment is applied to the rope. Therefore, they have the lower price among these three wire ropes. Generally, they are fully lubricated to protect the rope from rust and corrosion.

Galvanized steel wire ropes feature compressed zinc coating for providing excellent corrosion resistance. With higher break strength yet lower price than stainless steel, galvanized steel wire ropes are widely used in general engineering applications such as winches and security ropes.

Stainless steel wire ropes, made of quality 304, 305, 316 steels, are the most corrosive type for marine environments and other places subjected to salt water spray. Meanwhile, bright and shiny appearance can be maintained for years rather than dull as galvanized steel wire ropes.

Steel wire ropes are composed of multiple strands of individual wires that surrounding a wire or fiber center to form a combination with excellent fatigue and abrasion resistance. These wires and strands are wound in different directions to from different lay types as follows:

Beside above lay types, alternative lay ropes which combine regular lay and lang lay together and ideal for boom hoist and winch lines, can also be supplied as your request.

Two main methods about seizing steel wire ropes in conjunction with soft or annealing wire or strands to protect cut ends of the ropes form loosening.

We have ½" Galvanized Super Swaged Cable. For a smoother, quieter and faster zip line ride. This 6X26 Cable boast a 35,210 pound tensile strength. It is made by swaging 9/16" Wire Rope down to

A must when connecting cable to nut eye bolts or ovaleye bolts. Keeps the cable from flattening around the eye causing the cable to weaken. Also used in eyespliced ropes. *When using a guy thimble

Usually only used on cable or wire rope. Match the thimble size to your cable diameter. We offer an open pattern of the 3/8" which is gapped to fit onto our nut eye bolts and ovaleye bolts.

Wire Rope Clips are used to secure the end of wire rope when forming a loop; i.e., for wire rope turn-back. Clips are available in two configurations: mid-grip (double saddle) and single

Based on the catalog breaking strength of wire rope, Crosby wire rope clips have an efficiency rating of 80% for 1/8"-7/8" sizes, and 90% for sizes 1" through 3-1/2".

Meets or exceeds all requirements of ASME B30.26 including identification, ductility, design factor, proof load and temperature requirements. Importantly, these wire rope clips meet other

The CM Mid-Grip is designed for applications in the scaffolding industry. The redesigned mid-grip features a hexagon bolt head that fits securely into a forged, hex-shaped socket that prevents

Based on the catalog breaking strength of wire rope, Crosby wire rope clips have an efficiency rating of 80% for 3/16"-7/8", and 90% for sizes 1" through 1-1/2".

Meets or exceeds all requirements of ASME B30.26 including identification, ductility, design factor, proof load and temperature requirements. Importantly, these wire rope clips meet other

Fist Grip wire rope clips meet or exceed the performance requirements of Federal Specification FF-C-450 Type III, Class 1, except for those provisions required of the contractor. For additional

Apply the first clip one base width from the dead end of the wire rope. The base or saddle should bear on the line end of the rope - U-bolt on the short end. Tighten nuts firmly.

H2: Our company is located in Nantong, a coastal open city in the lower reaches of Yangtze River, near the first exit of Sutong Yangtze River Bridge in the south, Nantong port in the east and Nantong airport in the north. The company specializes in the production of various specifications of smooth, galvanized Steel Wire Rope, elevator Wire Rope, steel strand, Spring Steel Wire and galvanized, phosphating blank Steel Wire, the products are mainly sold to the United States, Europe, the Middle East, Southeast Asia, Africa and other regions and countries.

H2: Steel Wire Rope 6x19 compacted Wire Rope construction is available with either FC or IWRC. When supplied with a wire strand core the rope is more commonly referred to as 7x19. The rope is very popular in diameters from 3mm to 16mm and is used on a variety of applications. 6x19+FC and 6x19+IWRC (7x19) is very flexible in diameters 3mm to 6mm and is used for many applications where Wire Ropes are running over pulleys. 6x19+IWRC construction is readily available in both galvanised and marine grade stainless steel.

Wire rope and cable are each considered a “machine”. The configuration and method of manufacture combined with the proper selection of material when designed for a specific purpose enables a wire rope or cable to transmit forces, motion and energy in some predetermined manner and to some desired end.

Two or more wires concentrically laid around a center wire is called a strand. It may consist of one or more layers. Typically, the number of wires in a strand is 7, 19 or 37. A group of strands laid around a core would be called a cable or wire rope. In terms of product designation, 7 strands with 19 wires in each strand would be a 7×19 cable: 7 strands with 7 wires in each strand would be a 7×7 cable.

Materials Different applications for wire rope present varying demands for strength, abrasion and corrosion resistance. In order to meet these requirements, wire rope is produced in a number of different materials.

Stainless Steel This is used where corrosion is a prime factor and the cost increase warrants its use. The 18% chromium, 8% nickel alloy known as type 302 is the most common grade accepted due to both corrosion resistance and high strength. Other types frequently used in wire rope are 304, 305, 316 and 321, each having its specific advantage over the other. Type 305 is used where non-magnetic properties are required, however, there is a slight loss of strength.

Galvanized Carbon Steel This is used where strength is a prime factor and corrosion resistance is not great enough to require the use of stainless steel. The lower cost is usually a consideration in the selection of galvanized carbon steel. Wires used in these wire ropes are individually coated with a layer of zinc which offers a good measure of protection from corrosive elements.

Cable Construction The greater the number of wires in a strand or cable of a given diameter, the more flexibility it has. A 1×7 or a 1×19 strand, having 7 and 19 wires respectively, is used principally as a fixed member, as a straight linkage, or where flexing is minimal.

Selecting Wire Rope When selecting a wire rope to give the best service, there are four requirements which should be given consideration. A proper choice is made by correctly estimating the relative importance of these requirements and selecting a rope which has the qualities best suited to withstand the effects of continued use. The rope should possess:Strength sufficient to take care of the maximum load that may be applied, with a proper safety factor.

Strength Wire rope in service is subjected to several kinds of stresses. The stresses most frequently encountered are direct tension, stress due to acceleration, stress due to sudden or shock loads, stress due to bending, and stress resulting from several forces acting at one time. For the most part, these stresses can be converted into terms of simple tension, and a rope of approximately the correct strength can be chosen. As the strength of a wire rope is determined by its, size, grade and construction, these three factors should be considered.

Safety Factors The safety factor is the ratio of the strength of the rope to the working load. A wire rope with a strength of 10,000 pounds and a total working load of 2,000 pounds would be operating with a safety factor of five.

It is not possible to set safety factors for the various types of wire rope using equipment, as this factor can vary with conditions on individual units of equipment.

The proper safety factor depends not only on the loads applied, but also on the speed of operation, shock load applied, the type of fittings used for securing the rope ends, the acceleration and deceleration, the length of rope, the number, size and location of sheaves and drums, the factors causing abrasion and corrosion and the facilities for inspection.

Fatigue Fatigue failure of the wires in a wire rope is the result of the propagation of small cracks under repeated applications of bending loads. It occurs when ropes operate over comparatively small sheaves or drums. The repeated bending of the individual wires, as the rope bends when passing over the sheaves or drums, and the straightening of the individual wires, as the rope leaves the sheaves or drums, causing fatigue. The effect of fatigue on wires is illustrated by bending a wire repeatedly back and forth until it breaks.

The best means of preventing early fatigue of wire ropes is to use sheaves and drums of adequate size. To increase the resistance to fatigue, a rope of more flexible construction should be used, as increased flexibility is secured through the use of smaller wires.

Abrasive Wear The ability of a wire rope to withstand abrasion is determined by the size, the carbon and manganese content, the heat treatment of the outer wires and the construction of the rope. The larger outer wires of the less flexible constructions are better able to withstand abrasion than the finer outer wires of the more flexible ropes. The higher carbon and manganese content and the heat treatment used in producing wire for the stronger ropes, make the higher grade ropes better able to withstand abrasive wear than the lower grade ropes.

Effects of Bending All wire ropes, except stationary ropes used as guys or supports, are subjected to bending around sheaves or drums. The service obtained from wire ropes is, to a large extent, dependent upon the proper choice and location of the sheaves and drums about which it operates.

A wire rope may be considered a machine in which the individual elements (wires and strands) slide upon each other when the rope is bent. Therefore, as a prerequisite to the satisfactory operation of wire rope over sheaves and drums, the rope must be properly lubricated.

Loss of strength due to bending is caused by the inability of the individual strands and wires to adjust themselves to their changed position when the rope is bent. Tests made by the National Institute of Standards and Technology show that the rope strength decreases in a marked degree as the sheave diameter grows smaller with respect to the diameter of the rope. The loss of strength due to bending wire ropes over the sheaves found in common use will not exceed 6% and will usually be about 4%.

The bending of a wire rope is accompanied by readjustment in the positions of the strands and wires and results in actual bending of the wires. Repetitive flexing of the wires develops bending loads which, even though well within the elastic limit of the wires, set up points of stress concentration.

The fatigue effect of bending appears in the form of small cracks in the wires at these over-stressed foci. These cracks propagate under repeated stress cycles, until the remaining sound metal is inadequate to withstand the bending load. This results in broken wires showing no apparent contraction of cross section.

Experience has established the fact that from the service view-point, a very definite relationship exists between the size of the individual outer wires of a wire rope and the size of the sheave or drum about which it operates. Sheaves and drums smaller than 200 times the diameter of the outer wires will cause permanent set in a heavily loaded rope. Good practice requires the use of sheaves and drums with diameters 800 times the diameter of the outer wires in the rope for heavily loaded fast-moving ropes.

It is impossible to give a definite minimum size of sheave or drum about which a wire rope will operate with satisfactory results, because of the other factors affecting the useful life of the rope. If the loads are light or the speed slow, smaller sheaves and drums can be used without causing early fatigue of the wires than if the loads are heavy or the speed is fast. Reverse bends, where a rope is bent in one direction and then in the opposite direction, cause excessive fatigue and should be avoided whenever possible. When a reverse bend is necessary larger sheaves are required than would be the case if the rope were bent in one direction only.

Stretch of Wire Rope The stretch of a wire rope under load is the result of two components: the structural stretch and the elastic stretch. Structural stretch of wire rope is caused by the lengthening of the rope lay, compression of the core and adjustment of the wires and strands to the load placed upon the wire rope. The elastic stretch is caused by elongation of the wires.

The structural stretch varies with the size of core, the lengths of lays and the construction of the rope. This stretch also varies with the loads imposed and the amount of bending to which the rope is subjected. For estimating this stretch the value of one-half percent, or .005 times the length of the rope under load, gives an approximate figure. If loads are light, one-quarter percent or .0025 times the rope length may be used. With heavy loads, this stretch may approach one percent, or .01 times the rope length.

The elastic stretch of a wire rope is directly proportional to the load and the length of rope under load, and inversely proportional to the metallic area and modulus of elasticity. This applies only to loads that do not exceed the elastic limit of a wire rope. The elastic limit of stainless steel wire rope is approximately 60% of its breaking strength and for galvanized ropes it is approximately 50%.

Preformed Wire Ropes Preformed ropes differ from the standard, or non-preformed ropes, in that the individual wires in the strands and the strands in the rope are preformed, or pre-shaped to their proper shape before they are assembled in the finished rope.

This, in turn, results in preformed wire ropes having the following characteristics:They can be cut without the seizings necessary to retain the rope structure of non-preformed ropes.

They are substantially free from liveliness and twisting tendencies. This makes installation and handling easier, and lessens the likelihood of damage to the rope from kinking or fouling. Preforming permits the more general use of Lang lay and wire core constructions.

Removal of internal stresses increase resistance to fatigue from bending. This results in increased service where ability to withstand bending is the important requirement. It also permits the use of ropes with larger outer wires, when increased wear resistance is desired.

Outer wires will wear thinner before breaking, and broken wire ends will not protrude from the rope to injure worker’s hands, to nick and distort adjacent wires, or to wear sheaves and drums. Because of the fact that broken wire ends do not porcupine, they are not as noticeable as they are in non-preformed ropes. This necessitates the use of greater care when inspecting worn preformed ropes, to determine their true condition.