Steel cable 1 mm characteristics. steel cable, steel rope

Metal ropes and twisted slings based on them are necessary and critical elements of transport and construction equipment, industrial equipment and lifting devices. Steel wire ropes with organic and metal cores are used throughout. Interstate standard 2688-80 defines the types of double lay products with an organic core and a linear touch of steel wires.

Cables of a similar design, but with a metal central strand, are produced according to GOST 7668–80.

Steel rope GOST 2688–80 consists of six wire strands, which are twisted into one concentric surface around the organic core.

Natural and artificial materials are used as an organic core, such as:

• sisal;
• hemp;
• cotton yarn;
• kapron threads;
• nylon;
• polyethylene.

The core material is impregnated with a lubricant that protects it from decay and increases the life of the product. Lubricants GOST 15037–69 are mineral oils containing solid hydrocarbons and copper salts. The organic core provides the necessary resilience and flexibility to steel cables.

Each metal strand LK-R consists of 19 round wires twisted in three layers. The outer layer contains wires of different diameters, which ensures a linear type of contact in the strands, uniformity and strength of the rope surface. Cables with strands LK-R have high wear resistance and performance.

A design feature is the direction of twisting of the rope elements. The direction of twisting of the wire in the strands can be left or right. The combination of the directions of the elements during laying determines the properties of the cable. One-sided lay ropes are flexible, wear-resistant, but easily unwind under load. Non-twisting structures are made using the cross lay or combined lay methods.

Round wire for steel cables is made of uncoated carbon steel or with a galvanized outer layer.

Product range with organic core and steel wire shell, defines GOST 2688–80. Steel ropes are subdivided according to mechanical properties, purpose, type of wire material, lay method and direction, manufacturing accuracy and degree of balance.

Classification differences

Cables according to their purpose are divided into types:

1. GL - cargo people, which are used when lifting, lowering, moving people and goods.
2. G - cargo, they are used for transportation and fastening of goods.

According to mechanical properties, grades are distinguished:

• 1 - the quality is normal.
• VK - high quality.
• B - high quality.

Type of wire used:

• without external coating;
• with galvanized layer.

Depending on the density of zinc, the following types of galvanized wire are distinguished: OZH, S, ZH. Ropes made of wire coated with OZH are suitable for use in particularly harsh conditions and aggressive environments. For standard air service, uncoated or group C coated wire ropes are suitable.

In the direction of twisting the wire:

1. Left lay - denoted by the letter L.
2. Right lay - no designation.

According to the combination of wire and strand directions:

1. One-sided lay: with the same direction of the wires and strands in the rope.
2. Cross: with the opposite position of the wire and strands.
3. Combined: when strands of the right and left directions of twisting are used simultaneously when laying the cable.

By twisting method:

1. Non-twisting - denoted by the letter H.
2. Unwinding - without a symbol.

According to the accuracy of manufacturing, designs are distinguished:

• increased accuracy - T;
• normal.

For balance:

• not straightened;
• straightened - R.

The balance of a metal rope is determined by the fact whether straightening was used in the process of its production - straightening of the strands. This process takes stress off the cable so the product stays straight after twisting.

Symbol

All symbols specified in GOST, apply when marking ropes. The first digit of the marking is the diameter of the cable section, followed by the designation of the type of purpose, quality grade, coating group, lay direction, twisting characteristic, indication of straightening, accuracy and designation of the marking group.

For example: Rope 28 - G - 1 - L - 1670 GOST 2688–80. The designation of untwisted unfastened cables of the right lay, of normal manufacturing accuracy and of uncoated wire, will be shorter due to the lack of letters and numbers of the symbol. Only the diameter, purpose, quality group, left lay direction and marking group are indicated.

Straightened, non-twisting cables of increased quality and manufacturing accuracy, made of wire coated with coolant, will have the following marking: Rope 21 - GL - V - OZH - N - R - T - 1470 GOST 2688–80.

Marking groups, dimensions and weight

Last number in the designation of the rope - a marking group that indicates the strength characteristics of the rope. The larger the number, the stronger the cable and the greater the load that it can withstand during operation.

According to GOST 2688–80, ropes with a cross-sectional diameter of 3.6 to 56 mm are produced with strength characteristics from 1370 to 1860 N / mm 2 (140-190 kgf / mm 2). The tables of the standard indicate the diameters of the ropes, all wire layers of the strands, strength characteristics and the approximate weight of 1 thousand meters of the rope. The weight of a steel rope GOST 2688–80 can be determined by multiplying the weight value of 1 thousand meters of the cable, taken from the table, by the length of the rope and dividing the resulting value by 1000.

1 thousand meters of rope with a diameter of 12 mm weighs approximately 520 kg; with a diameter of 21 mm - 1630 kg. The weight of one meter of a product with a thickness of 37 mm will be approximately 5 kg, and one meter with a thickness of 56 mm - 11.6 kg.

GOST 2688-80

Group B75

INTERSTATE STANDARD

DOUBLE TWAY ROPE TYPE LK-R DESIGN 6x19(1+6+6/6)+1 o.s.

Assortment

Two lay rope type LK-R construction 6x19 (1+6+6/6)+1 o.c. Dimensions

ISS 77.140.65
OKP 12 5100, 12 5200

Introduction date 1982-01-01

By the Decree of the State Committee of the USSR for Standards of April 23, 1980 N 1833, the date of introduction was set to 01.01.82

The validity period was removed by the Decree of the State Standard of November 22, 1991 N 1752

INSTEAD OF GOST 2688-69

Edition (May 2011) with Amendments No. 1, 2, approved in November 1986, November 1991 (IUS 2-87, 2-92)

1. This standard applies to double lay steel ropes with a linear touch of the wires in strands of the LK-R type with one organic core.

2. Ropes are subdivided according to features

by appointment:

cargo people - GL,

cargo - G;

according to the mechanical properties of grades: VK, V, 1;

according to the type of surface coating of the wires in the rope:

uncoated wire,

from galvanized wire, depending on the surface density of zinc: C, W, OZH;

in lay direction:

right,

left - L;

by combination of lay directions of rope elements:

cross,

one-sided - Oh,

combined - K;

by twisting method:

non-spinning - N,

unwinding;

manufacturing accuracy:

normal,

elevated - T;

according to the degree of balance:

straightened - P,

not straightened.

Legend Examples

Rope with a diameter of 12.0 mm, for cargo purposes, from uncoated wire, grade B, left-hand one-sided lay, non-twisting, non-straightened, increased accuracy, marking group 1770 N/mm (180 kgf/mm):

Rope 12-GL-V-L-O-N-T-1770 GOST 2688-80

The same, with a diameter of 32.0 mm, for cargo purposes, grade I, galvanized according to the coolant group, right-hand cross lay, non-twisting, non-straightened, normal accuracy, marking group 1370 N/mm (140 kgf/mm):

Rope 32-G-I-OJ-N-1370 GOST 2688-80

3. The diameter of the rope and its main parameters must correspond to those indicated in the table.

Continuation

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Notes:

1. Ropes, the breaking force of which is given to the left of the thick line, are made from uncoated and galvanized wire. Ropes made of galvanized wire of groups Zh and OZH with diameters of 51.0 and 56.0 mm of the marking group 1370 N/mm (140 kgf/mm), 42.0-47.5 mm of the marking group 1470 N/mm (150 kgf/mm) , 30.5-47.5 mm marking group 1570 N/mm (160 kgf/mm), 30.5-39.5 mm marking group 1670 N/mm (170 kgf/mm), 21.0-33.5 mm of the marking group 1770 N/mm (180 kgf/mm), 11.0-16.5 mm of the marking group 1960 N/mm (200 kgf/mm) are produced by agreement between the manufacturer and the consumer.

Ropes, the breaking force of which is given to the right of the thick line, are made from uncoated wire. It is allowed, by agreement between the manufacturer and the consumer, to manufacture ropes from galvanized wire.

2. Rope diameters over 10 mm are rounded to the nearest integer or 0.5 mm.


2, 3. (Changed edition, Rev. N 1, 2).

4. Technical requirements, acceptance rules, test methods, marking, packaging, transportation and storage in accordance with GOST 3241-91.



Electronic text of the document
prepared by Kodeks JSC and verified against:
official publication
Steel ropes. Assortment: Collection of GOSTs. -
M.: Standartinform, 2011

Steel cable is recommended for a wide range of applications in various lifting devices, from hand hoists to cranes, for lifting and moving loads, parts and structural elements. The steel cable is part of most lifting mechanisms and devices. Depending on the design, the steel cable has different flexibility and stretching coefficient. The steel cable is made of carbon steel and galvanized. Structurally, the steel cable is made of high-strength wire and core. The wire is wrapped around the core and get a strand, the strands, in turn, are also wrapped around the core and get a steel cable.

An example of the designation of a steel cable: 6 x 7 + FC.

The first number is the number of rope strands.

The second is the number of wires in the strand.

The third is the number of cores, including the cores in the strands, if there is no number - a non-metallic one in the center of the steel cable, and a steel core in the strands.

Letters - core material: FC - vegetable, PVC - synthetics. If there is no letter designation, this means that the same strand as the side ones is used as the central core.

The information below on the classification of ropes is far from new, and we can hardly add anything new. You can easily find similar materials on other resources, so why do we host it? Looking at the classification below, you will understand that there are a large number of types of rope and sometimes even a specialist can be quite difficult to figure out what Rope 12-GL-VK-L-O-N-1770 GOST 2688–80 is.

Working with the same ropes, deciphering everything is easy enough, but if the client wants to buy a non-standard rope? This is where “Where to look? Where to get? What does this letter mean in the name? We have previously published material about ropes, but did not describe the classification in detail, so we hope that this article will be useful to you.

Classification, technical requirements, test methods, rules for acceptance, transportation, and storage of steel ropes are set out in GOST 3241-91 “Steel ropes. Specifications".

Classification of steel ropes

1. According to the main design feature:

• single lay or spiral consist of wires twisted in a spiral in one or more concentric layers. Ropes of a single lay, twisted only from round wire, are called ordinary spiral ropes. Spiral ropes with shaped wires in the outer layer are called ropes of a closed structure. Single lay ropes intended for subsequent laying are called strands.
• double lay consist of strands twisted in one or more concentric layers. Double lay ropes can be single-layer or multi-layer. Single-layer six-strand double lay ropes are widely used. Double lay ropes intended for subsequent laying are called strands.
• triple lay consist of strands twisted in a spiral into one concentric layer.

2. According to the shape of the cross section of the strands:

• round
• shaped yarn(triangular strand, flat strand), have a significantly larger contact surface to the pulley than round strand.

3. According to the type of lay of strands and ropes of a single lay:

• TC- with a point touch of the wires between the layers,
• OK- with a linear touch of the wires between the layers,
• LK-O- with a linear touch of the wires between the layers with the same diameter of the wires in the layers of the strand,
• LK-R- with a linear touch of the wires between the layers at different diameters of the wires in the outer layer of the strand,
• LK-Z- with a linear touch of the wires between the layers of the strand and the filling wires,
• LK-RO- with a linear touch of the wires between the layers and having layers with wires of different diameters and layers with wires of the same diameter in strands,
• TLC- with a combined point-line touch of the wires in the strands.

Strands with a point touch of the wires are made in several technological operations, depending on the number of layers of wires. In this case, it is necessary to apply different wire laying steps for each layer of the strand and twist the next layer in the opposite direction to the previous one. As a result, the wires between the layers intersect. Such an arrangement of wires increases their wear during shear during operation, creates significant contact stresses that contribute to the development of fatigue cracks in the wires, and reduces the filling factor of the rope section with metal.
Strands with a linear touch of the wires are made in one technological step; at the same time, the lay pitch is maintained, and the same direction of the wire lay for all layers of the strand, which, with the correct selection of wire diameters by layers, gives a linear touch of the wires between the layers. As a result, the wear of the wires is significantly reduced and the performance of ropes with a linear touch of the wires in the strands increases sharply in comparison with the performance of ropes of the TK type.
Strands of point-linear touch are used if it is necessary to replace the central wire in the strands of linear touch with a seven-wire strand, when a layer of wires of the same diameter with point touch is laid on a single-layer seven-wire strand of the LK type. The strands may have increased non-rotating properties.

4. According to the core material:

• OS- with an organic core - as a core in the center of the rope, and sometimes in the center of the strands, cores made of natural, synthetic and artificial materials are used - from hemp, manila, sisal, cotton yarn, polyethylene, polypropylene, capron, lavsan, viscose, asbestos .
• MS- with a metal core - as a core, in most designs, a double lay rope of six seven wire strands is used, located around the central seven wire strand, in ropes according to GOST 3066-80, 3067-88,3068-88 a strand is used the same construction as in the layer. They are advisable to use when it is necessary to increase the structural strength of the rope, reduce the structural elongation of the rope in tension, as well as at high temperatures of the environment in which the rope operates.

5. According to the laying method:

• Non-twisting ropes - H- the strands and wires retain their predetermined position after the bindings are removed from the end of the rope or are easily laid by hand with slight untwisting, which is achieved by preliminary deformation of the wires and strands when twisting the wires into a strand and strands into a rope.
• Unwinding ropes- wires and strands are not preliminarily deformed or insufficiently deformed before they are twisted into strands and into a rope. Therefore, the strands in the rope and the wires in the strands do not retain their position after the bindings are removed from the end of the rope.

6. According to the degree of balance:

• Straightened rope - P- does not lose its straightness (within the permissible deviation) in a free suspended state or on a horizontal plane, because after twisting the strands and spar, respectively, the stresses from the deformation of the wires and strands were removed by straightening.
• Unaligned rope- does not have such a property, the free end of the untied rope tends to form a ring, due to the deformation stresses of the wires and strands obtained during the rope manufacturing process.

7. In the direction of the lay of the rope:

• Right lay- not marked
• Left lay- L

The direction of the rope lay is determined by: the direction of the lay of the wires of the outer layer - for single lay ropes; the direction of the lay of the strands of the outer layer - for double lay ropes; the direction of the lay of the strands into the rope - for triple lay ropes

8. According to the combination of lay directions of the rope and its elements:

• Cross lay- the direction of the lay of strands and strands is opposite to the direction of the lay of the rope.
• One-sided lay - O- the direction of laying the strands into the rope and the wires in the strands are the same.
• Combined lay- K with simultaneous use of strands of the right and left lay directions in the rope.

9. According to the degree of twist

• spinning- with the same lay direction of all strands along the layers of the rope (six- and eight-strand ropes with an organic and metal core)
• Low spinning- (MK) with the opposite direction of the lay of the rope elements in layers (multilayer, multi-strand ropes and single lay ropes). In non-rotating ropes, due to the selection of lay directions for individual layers of wires (in spiral ropes) or strands (in multilayer double-lay ropes), the rotation of the rope around its axis is eliminated when the load is freely suspended.

10. According to the mechanical properties of the wire

• Brand VK- High Quality
• Grade B- high quality
• Mark 1- normal quality

11. According to the type of coating of the surface of the wires in the rope:

• From uncoated wires
• Made of galvanized wire depending on the surface density of zinc:
• group C- for medium aggressive working conditions
• group G- for tough aggressive working conditions
• coolant group- especially severe aggressive working conditions
• P- the rope or strands are coated with polymeric materials

12. According to the purpose of the rope

• cargo people - GL- for lifting and transporting people and goods
• Freight - G- for lifting and transporting and cargo

13. Manufacturing accuracy

• normal precision- not marked
• Increased accuracy - T- toughened limit deviations for the diameter of the rope

14. According to strength characteristics
Marking groups of tensile strength N/mm2 (kgf/mm2) - 1370 (140), 1470 (150), 1570 (160), 1670 (170), 1770 (180), 1860 (190), 1960 (200), 2060 (210), 2160 (220)

Examples of symbols for steel ropes

1. Rope 16.5 - G - I - N - R - T - 1960 GOST 2688 - 80 Rope with a diameter of 16.5 mm, cargo use, first grade, made of uncoated wire, right cross lay, non-twisting, straightened, increased accuracy, marking group 1960 N/mm2 (200 kgf/mm2), according to GOST 2688 - 80
2. Rope 12 - GL - VK - L - O - N - 1770 GOST 2688 - 80 Rope with a diameter of 12.0 mm, for human cargo, grade VK, made of uncoated wire, left one-sided lay, non-twisting, non-aligned, normal accuracy, marking group 1770 N/mm2 (180 kgf/mm2), according to GOST 2688-80
3. Rope 25.5 - G - VK - S - N - R - T - 1670 GOST 7668 - 80 Rope with a diameter of 25.5 mm, cargo, grade VK, galvanized according to group C, right cross lay, non-twisting, straightened, increased accuracy , marking group 1670 N/mm2 (170 kgf/mm2), according to GOST 7668 - 80
4. Rope 5.6 - G - V - Zh - N - MK - R - 1670 GOST 3063 - 80 Rope with a diameter of 5.6 mm, cargo purpose, grade B, galvanized according to group Zh, right lay, non-twisting, low-rotation, straightened, marking group 1670 N/mm2 (170 kgf/mm2), according to GOST 3063 - 80

Each rope design has advantages and disadvantages that must be properly considered when choosing ropes for specific operating conditions. When choosing, it is necessary to maintain the necessary ratios between the diameters of the winding bodies and the diameters of the ropes and their outer wires, as well as the necessary margin of safety, which ensures trouble-free operation.

Ropes of a single lay from round wires - ordinary spiral (GOST 3062-80; 3063-80; 3064-80) have increased rigidity, so they are recommended to be used where tensile loads on the rope prevail (lightning protection cables of high-voltage power lines, fences, stretch marks, etc.)

Double lay ropes with linear contact of wires in strands with ease of manufacture, they have a relatively high performance and have a sufficient number of various designs. The latter allows you to choose ropes for operation at high end loads, with significant abrasive wear, in various aggressive environments, with the minimum allowable ratio of the diameter of the winding body and the diameter of the rope.

Ropes type LK-R (GOST 2688-80, 14954-80) should be used when during operation the ropes are exposed to aggressive environments, intense alternating bending and work outdoors. The high structural strength of these ropes allows them to be used in many very demanding crane operating conditions.

Ropes type LK-O (GOST 3077-80, 3081-80; 3066-80; 3069-80; 3083-80) work stably in conditions of strong abrasion due to the presence of larger diameter wires in the upper layer. These ropes are widely used, but their normal operation requires a slightly increased diameter of blocks and drums.

Ropes type LK-Z (GOST 7665-80, 7667-80) used when flexibility is required, provided that the rope is not exposed to an aggressive environment. The use of these ropes in aggressive environments is not recommended due to the thin filler wires in the strands, which are easily corroded.

Ropes type LK-RO (GOST 7668-80, 7669-80, 16853-80) are characterized by a relatively large number of wires in the strands and therefore have increased flexibility. The presence of relatively thick wires in the outer layer of these ropes allows them to be successfully used in conditions of abrasive wear and aggressive environments. Due to this combination of properties, the LK-RO type construction rope is universal.

Double-lay ropes with point-linear contact of wires in strands of the TLC-O type (GOST 3079-80) should be used when the use of ropes with a linear touch of the wires in the strands is impossible due to a violation of the minimum allowable adjustment ratios between the diameters of the winding elements and the diameters of the wires of the rope or when it is impossible to provide the recommended safety margin.

Double lay ropes with point contact of wires in strands of TK type (GOST 3067-88; 3068-88; 3070-88; 3071-88) not recommended for critical and intensive installations. These ropes can only be used for non-stressful operating conditions, where alternating bends and pulsating loads are not significant or absent (slings, brace ropes, temporary timber-rafting supports and brake ropes, etc.)

Multi-strand double lay ropes (GOST 3088-80; 7681-80) depending on the accepted directions of laying strands in separate layers, they are made ordinary and non-rotating. The latter provide reliable and stable operation on mechanisms with free suspension of the load, and a large supporting surface and lower specific pressures on the outer wires make it possible to achieve a relatively high rope performance. The disadvantages of multi-strand ropes are the complexity of manufacturing (especially pre-deformation), the tendency to delamination, the difficulty of monitoring the state of the inner layers of the strands.

Triple lay ropes (GOST 3089-80) are used when the main operational requirements are maximum flexibility and elasticity of the rope, and its strength and bearing surface are not critical. Organic cores in strands are appropriate when the rope is intended for towing and mooring, where increased elastic properties of the rope are required. Due to the use of small diameter wires compared to the wires of double lay ropes, triple lay ropes require significantly smaller diameter sheaves for normal operation.

Trihedral strand ropes (GOST3085-80) characterized by increased structural stability, a very high fill factor and a large bearing surface. The use of these ropes is especially advisable for high end loads and strong abrasive wear. It is recommended to use these ropes both in installations with friction pulleys and in multilayer winding on drums. The disadvantage of triangular-strand ropes is sharp bends of the wires on the edges of the strands, increased rope rigidity, and laboriousness in the manufacture of strands.

Flat ropes (GOST 3091-80; 3092-80) find application as balancing on mine lifting installations. The advantages of these ropes include their non-torsion. However, the manual operations used in the sewing of the ropes and the relatively rapid destruction of the thong during operation limit the scope of use of these ropes in the industry.

Classification of ropes according to domestic and foreign standards