Steel wire rope
Human civilization is in constant motion, we are inventing new technology and various devices that simplify our life, making it simpler and safer. One of the most significant inventions was the wire, which later served as the basis for the steel rope.
Metal cables are made from wire of different quality, depending on the purpose for which the cable will serve, which is twisted in a spiral. The material for the wire is made from steel saturated with carbon, which is zinc-treated on top. Such a product is called galvanized rope and is more durable, however, with prolonged use, the coating is erased. Also, the wire for most models of ropes is subject to thermal effects, which can significantly improve its quality.
The history of the creation of the steel cable
Steel products that resemble a modern cable have been known to mankind for several thousand years. The ancient Egyptians were the first to use this invention, who passed metal through holes of different diameters, as a result of which a wire was cast, which people used for various purposes. For example, for the production of various objects, in construction, for jewelry and even for fixing dentures.
Subsequently, the bundles of wire began to be intertwined according to the principle of a rope or rope, which allowed them to be much stronger.
In the 19th century, lifting mechanisms were invented, which required strong and reliable cables. It was then that the history of industrial production and mass use of steel cables began.
Until 1840, such products were classified as wire products, because they were woven by hand, but when a special mechanism was invented that made it possible to automate this process, the product began to be called "steel rope".
Thanks to the development of technologies and the discovery of new alloys, metal cables began to be made from more reliable and durable materials. The steel ropes consisted of more than 17 thousand fine wires, 0.3 mm thick. That is why, after a while, the massive construction of suspension bridges began. Such bridges could withstand a colossal load - up to 100 thousand tons.
Where are metal cables used?
Now such cables are actively used in many areas of activity:
• in shipping;
• when processing oil;
• during construction;
• in mines;
• for household purposes.
Most often, a metal cable is used during towing and rigging, as well as when moving heavy loads. Due to their reliability and flexibility, such products have become the main material that is installed on cranes, excavators and drilling equipment. In addition, the product is used in elevators for the movement mechanism, as well as for the reinforcement of concrete structures.
However, the most common use of metal ropes is in lifting operations. This is due to the fact that the structure of the cable is extremely strong, withstands a strong breaking load, but at the same time the cable is elastic. Thanks to these characteristics, the cables are used to produce load-gripping mechanisms that can withstand colossal weight.
When choosing a steel cable, you should take into account the scope of use, as well as its specifics and various other circumstances in which the cable will be used. Indeed, not only the productivity of the work performed, but also the safety of workers directly depends on its type and section. It is for this reason that it is necessary to use cables that will correspond to the conditions of their operation and will be able to withstand all expected loads.
Please note that strict requirements also apply to the various additional components that are used in conjunction with steel cables. Before starting their operation, these products must pass various tests, which will confirm the serviceability of the structure and the safety of use. After that, a certificate of conformity is issued for all such products, which allows them to be used.
The choice of metal cables should be based on indicators of reliability, tensile strength, flexibility and load capacity. It is worth paying attention to the fact that if the cable is planned to be used in an aggressive environment, then this must be taken into account. Also extremely important in certain areas is the weight of the product, which can affect the quality and productivity of work.
Types of cables and their marking
When choosing a metal cable, it is necessary to take into account many different factors: diameter, type of construction, length, elasticity, maximum load. Separately, you should pay attention to the design features, which are key in the selection of a product for a particular type of activity.
Such products consist of a steel strand, which is wound according to a certain algorithm, as well as a base. There are cables from one and several layers. Multi-layer products can support a lot of weight and do not twist when used, which is key in certain industries.
Type of constructions and the product is determined by the number of turns. For example, a single metal cable consists of a base with a wire wound around it in a spiral. It is necessary to pay attention to the fact that more complex products are often produced from single cables.
The most technically difficult to manufacture are ropes with three turns. For their manufacture, special elements are used - strands. These are special double braided steel ropes. They are produced in order to make more reliable and complex products on their basis.
To determine the type of strand, use the LC type marking (indicator of the level of linear tangency). The simplest strands are marked LK-0, since they are made with the same type of weaving on all layers, and also have a completely identical pattern, which is constantly repeated.
It should be noted that such strands can be produced from wire of various cross-sections. In such a situation, the product receives the LK-R marking. In addition, mixed types of strands of different designs, with wire of different cross-sections, are common. They are labeled LK-RO. The method of production of strands must be taken into account in the selection of a product, because the characteristics of efficiency, reliability and durability directly depend on this parameter.
For the production of these products, the point-touch method is also used. These products are marked with TC. A unique feature of the design is the different step lengths in layers that cross each other. It should be mentioned that such cables should not be used where they will be subject to high dynamic loads.
This is due to a rather low indicator of the level of density of the structure, due to which friction arises under the influence of a dynamic load, as a result of which the cable can quickly become unusable.
Also, with the combination of TC and LK technologies, combined cables are produced. These products are marked with the TLC designation.
It should be noted that all types of products described above should be used for specific tasks. It should be understood that choosing the wrong steel rope will not only significantly reduce the productivity of the work, but can also be dangerous for employees who work in the immediate vicinity. It is for this reason that it is necessary to take a responsible approach to the choice of the type of cable, taking into account the operating conditions.
Types of weaving cables and their design features
Due to the wide distribution and high level of demand for metal cables, they are produced using various technologies. However, certain patterns have formed that need to be considered.
Modern types of wire rope use a large number of wires that are tightly woven around a base called a core. It should be noted that the cores are made from different types of materials, which are not necessarily metal. The rope itself is formed around the base. Also, the base protects the cable from being pushed through when exposed to strong pressure. If the base is made of metal, then it is coated with special solutions or a base is formed from aluminum or zinc. This is necessary to protect the structure from rust.
Often, ropes are made with a core made of organic material. It should be understood that these materials can quickly deteriorate due to various factors. It is for this reason that organic cores are impregnated with special solutions that allow them to extend their term of use.
At present, the mass production of cables with a synthetic polyamide core has begun. Most often, such cables are two-layer, and the design is made in such a way that a synthetic layer passes between the metal layers, which will protect the cable from chafing. The indisputable advantage of this design is the reduction in the total weight of the cable, which often plays a key role.
If the core is made of metal, then for the production of such a structure, special steel structures twisted in a spiral can be used.
According to the degree of elasticity, metal cables can be conditionally divided into the following types:
1. The least flexible, the base of which is made of 42 diameter wire and hemp.
2. Standard, which are made of wire of 72 diameters and twisted into strands separated from each other.
3. High elasticity, with a base of 144 diameter wire and six strands.
Where is used
Currently, the most widespread is the galvanized wire rope. In order to protect this product from the effects of rust, it is enclosed in a PVC casing, which allows it to be used in almost any conditions. The most common diameters are 3mm, 6mm, 8mm and 10mm. This thickness is optimal for most applications. For example, such ropes are used in the installation of a match in shipping, installation of antennas, communication lines and electrical communications, as well as for suspending a load that is immersed in a liquid.
Thanks to the introduction of modern technologies into this area, Special cables with a metal-polymer construction were made. At the same time, galvanizing technology is used, which gives the product additional reliability.
However, there is another way that allows you to protect the steel rope from the effects of corrosion. Such cables are coated with special lubricants, which allows the product to last much longer. For harsh operating conditions, special cables are produced that are resistant to temperature.