Steel cable 14 mm breaking load. Types of steel ropes, production, marking, rejection. Advantages of galvanized ropes

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 linear tangency of steel wires.

Ropes of a similar design, but with a metal central strand, are produced in accordance with GOST 7668-80.

Steel rope GOST 2688-80 consists of six wire strandswhich are twisted into one concentric surface around an organic core.

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

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

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

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

The design feature is the twisting direction of the rope elements. The direction of twisting of the wire in the strands can be left and right. The combination of directions of elements during lay-up sets the properties of the cable. One-sided lay ropes are flexible, wear-resistant, but easily untwisted under load. Non-unrolling structures are made by means of cross or combined stranding.

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

Organic core steel wire product range shell, defines GOST 2688–80. Steel ropes are subdivided according to their mechanical properties, purpose, type of wire material, method and direction of stranding, according to manufacturing accuracy and degree of balance.

Classification differences

According to the purpose, cables are divided into types:

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

According to mechanical properties, brands are distinguished:

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

By the type of wire used:

without outer cover;
with a galvanized layer.

Depending on the density of zinc, the following types of galvanized wire are distinguished: Coolant, C, Zh. Wire ropes with coolant coating are suitable for use in particularly harsh conditions and aggressive environments. For standard operating conditions in air, wire ropes of uncoated or coated group C are suitable.

In the direction of wire twisting:

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

By a combination of wire and strand directions:

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

By lay method:

Non-expanding - denoted by the letter N.
Unrolling - no symbol.

According to the manufacturing accuracy, structures are distinguished:

increased accuracy - T;
normal.

By balance:

unaligned;
flattened - 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 relieves stress on the rope, so the product remains 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, direction of the lay, curl 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 non-aligned right lay cables, normal manufacturing accuracy and uncoated wire will be shorter due to the absence of letters and numbers of the conventional designation. Only the diameter, purpose, quality group, left lay direction and marking group are indicated.

Straightened, non-twisting cables of high quality and manufacturing accuracy, made of wire coated with coolant, will have the following marking: Rope 21 - GL - V - ОЖ - Н - Р - Т - 1470 GOST 2688-80.

Marking groups, dimensions and weight

The last numeral in the designation of the rope - a marking group that indicates the strength characteristics of the rope. The higher the number, the stronger the cable and the more load that it can withstand during operation.

According to GOST 2688-80, ropes with a cross-sectional diameter from 3, 6 to 56 mm with strength characteristics from 1370 to 1860 N / mm 2 (140-190 kgf / mm 2) are produced. The tables of the standard indicate the diameters of ropes, all wire layers of strands, strength characteristics and an approximate weight of 1 thousand meters of rope. The weight of a steel rope GOST 2688-80 can be determined by multiplying the weight value of 1 thousand meters of rope 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.

Steel ropes have found applications in various industries and construction. Oil refining, coal mining, construction of industrial facilities and residential buildings, operation of sea and river vessels - this is not a complete list of applications for metal cables.

Scope of application

The main purpose of the wire rope is to perform rigging, towing and lifting operations. High strength combined with flexibility allows the use of metal products of this category for equipping lifting equipment and heavy equipment. This includes drilling equipment, cranes, excavators. In addition, steel wire ropes are used in the production of lifting and lowering mechanisms for cargo and passenger elevators.

Hoist ropes with linear touch of wires are used to create:

lifting equipment in metalworking shops;
mine lifting equipment;
drilling rigs and mining machines;
earthmoving and road machinery;
suspension roads.

Steel cables are used to equip ship cranes and truck cranes, telphers, winches and scrapers, lifts, drum winches and hydraulic lifts.

The valuable properties of a metal cable include its flexibility and the ability to manufacture load-gripping devices that can withstand serious mechanical stress. Steel cables and additional elements, in combination with which they are used, are subject to strict requirements for compliance with state standards.

Excellent mechanical characteristics and corrosion resistance make it suitable for use in the construction of critical structures - bridges, overpasses. Concrete structures, reinforced with a metal cord, acquire the necessary strength, the ability to work out large dynamic and static loads.

The main parameters for the selection of ropes are flexibility, strength, carrying capacity, as well as the limiting values \u200b\u200bof their tension. To increase the resistance of metal products to aggressive environments, they can be subjected to additional processing. The scope of application of the rope depends on the material of manufacture, purpose and brand.

Description

Steel rope GOST 2688-80 is a metal product that consists of an organic core and stranded steel wires. The core is the basis of the design and gives the product flexibility. It acts as a shock absorber, resists radial pressure when the rope is loaded and prevents its lateral deformation.

It can be executed from:

polypropylene, polyethylene;
hemp or cotton fiber;
viscose, nylon, lavsan;
cord, sisal.

To protect the core from premature destruction and decay, it is impregnated with special anti-corrosion compounds that do not contain acids and alkalis. Rope lubricants are used to impregnate the core:

Torsiol-55;
Elaskon;
BOZ-1;
SK-50;
KS-U.

During operation, when the rope is bent, the grease penetrates into the gaps between the wires, ensuring their uniform lubrication and protection of the metal from corrosion. Thanks to rope lubrication, long-term preservation of the core is ensured, friction and wear of internal and external wires is reduced when the rope is operated on blocks. The grease retains its qualities in a wide range of operating temperatures from -50 C to +50 C. Protective grease is used both in the manufacture of products and during operation. The composition is applied in a continuous layer with a thickness of at least 0.2 mm.

A double lay metal rope consists of six strands, which are made from wires of different diameters in the outer layer of the strands. Structural diagram of the rope6 × 19 (1 + 6 + 6/6) +1 o.c. This design minimizes the risk of rupture and deformation of the product.

Ropes with linear touch of wires of the LK-R type have a high efficiency, which allows them to be used for work in difficult conditions. Products in this category are resistant to abrasion and high end loads. Thanks to a wide range of standard sizes, you can select a product with optimal technicalcharacteristics.

Specifications

Steel ropes manufactured in accordance with GOST 2668-80 have a cross-sectional diameter of 3.6 mm to 56.0 mm. Products are classified according to several criteria. Ropes of increased manufacturing accuracy are designated by the index T. Depending on the purpose, they are:

GL - gruzolyudskim, intended for installation on elevators;
G - cargo, which are used for the installation of all other mechanisms.

Steel cables are made with right (P) and left lay, which is designated by the index L. Lay direction is:

K - combined;
O - one-sided;
cross.

According to the method of stranding the strands, the ropes are divided into:

H - non-rotating;
MK - low-rotating;
unwinding.

The use of combined and cross-lay ropes reduces the torsion of the suspended load. The uniform direction of the lay of the wires creates a high degree of twist. The opposite direction of the twisted strands gives the effect of low twist (MK). Products with the H marking have a number of advantages over other types:

during operation they do not form loops and knots;
free ends do not unwind or unfold;
the cable does not make circular rotations when cutting, removing bandages.

Depending on the degree of balance, the ropes are straightened (P) and non-straightened. As a result of straightening, the stress from the deformation of wires and strands disappears. The product retains its straightness both on a horizontal plane and in a free suspended state.

By mechanical properties, products are divided into brands:

B - ordinary quality;
VK - high quality;
1 - normal quality.

The material for production is steel wire with and without zinc coating. The surface density of zinc depends on the diameter of the wire.

Products with the letter designation C are operated in aggressive conditions. The density of zinc is 20-110 g / m2.
Ropes marked with the letter Ж have a coverage density of 25-150 g / m2 and are used in harsh conditions.
Products marked with coolant are intended for use in particularly harsh conditions with a high level of wear. The surface density of zinc varies from 60 to 245 g / m2.

Legend

Product labeling contains complete information about the type and brand of products. An example of a symbol is a rope 14-G-VK-L-K-MK-T-1860 GOST 2688-80. Decoding:

14 - rope diameter;
G - cargo;
VK - high quality;
L - with the left direction of the lay;
MK - low-rotating;
T - increased accuracy;
1860 - marking group.

Features of the production of ropes

Galvanized wire ropes are highly resistant to corrosion and are used in the following areas:

on timber floating and woodworking industry;
transport construction and shipbuilding, aircraft construction;
in metallurgy and mining industry;
production of construction equipment;
in the creation of production lines.

Price the product depends on its diameter, type and grade of steel used. The material for the manufacture of metal ropes is a low-alloy steel rope wire. It has a round cross-section and is made of special wire rod of the PK, VK, KK classes, which ensures high plasticity of the finished product. By surface type, rope wire is divided into:

light, without zinc coating with a diameter of 0.2 to 4.6 mm;
galvanized, with a diameter of 0.18-4.5 mm.

Structural and spring-spring steel grades 45-85 are used as raw materials for the manufacture of wire. The choice of steel grade depends on the purpose of the final product. Reinforcing ropes are made from steel 70, 75, 80, 85. For aviation ropes, wire is made from steel grades 50.55, 60, 65.

It is possible to use corrosion-resistant steel grades5Х17Н12Мо2, 17Х12Н7, 5Х17Н12М2. Steel alloyed with silicon, manganese, chromium, nickel and molybdenum shows good anti-corrosion properties and is resistant to atmospheric moisture.

Quality control

Steel ropes used in production require regular inspection. The detected defects are checked against the norms of rejection of products of this category. Marriage includes:

change in configuration and destruction of the core;
squeezing wires out of strands;
wear of the outer layer of wires;
wire breakage;
a rope hall.

If such defects are found, the product is rejected.

Measuring the rope diameter

The diameter of the rope is determined by measuring the actual size of the product using a vernier caliper. Measurements are carried out in two sections, the distance between which is at least 1 m. In each section, the diameter is measured in two planes. The arithmetic mean of the four measurements must be within the permissible limits indicated for the nominal diameter.

Ropes packing

Buythe product can be in coils, wound on wooden or metal spools. The length of the rope in the coil depends on its diameter and is 200, 500 and 1000 m. When placing an order, the required rope length is indicated in the contract concluded withmanufacturer.

The maximum deviation in length should not exceed 5% for ropes with a length of less than 400 m. For products with a length of more than 400 m, the allowable deviation is 20 m for every 1000 m.

internal diameter of at least 15 product diameters;
outer diameter no more than 1.2 m;
height no more than 0.8 m.

It is allowed to wind several lengths of rope of the same standard size onto the reel. In this case, the ends are firmly fixed, the outer end is bound and fixed on the inner side of the coil cheek. Used for strapping: strands, ropes, tapes, wire, organic core.

At the request of the customer, the GL ropes are wrapped in polymer film or waterproof paper, the coils are sheathed with boards. The coils are firmly tied with soft wire or strands of rope at four or six points, while the fastening areas should be evenly spaced around the circumference of the coil. Packaging of products that are shipped to the northern regions or sent by sea is carried out in accordance with GOST 15846-79.

Each rope is supplied with a certificate and a tag that is attached to the reel or coil. It indicates the serial number of the product, symbols, length and weight parameters.

Rope weight

Steel ropes are elements of lifting mechanisms and devices. To use the equipment efficiently, accurate information about the parameters of the rope - technical characteristics, diameter,mass, how many meters per ton. Weight 1 meterthe product depends on its diameter, which consists of the diameters of the wires - the central, inner and outer layers.

Rope diameter, mm	Running meter weight, kg	Weight of 1000 m oiled rope, kg	Number of meters per ton
3,6	0,049	48,8	20408,2
3,8	0,055	55,1	18181,8
4,1	0,064	64,1	15625,0
4,5	0,074	73,9	13513,5
4,8	0,084	84,4	11904,8
5,1	0,096	95,5	10416,7
5,6	0,117	116,5	8547,0
6,2	0,142	141,6	7042,3
6,9	0,177	176,6	5649,7
7,6	0,211	211,0	4739,3
8,3	0,256	256,0	3906,3
9,1	0,305	305,0	3278,7
9,6	0,359	358,6	2785,5
11,0	0,462	461,6	2164,5
12,0	0,527	527,0	1897,5
13,0	0,597	596,6	1675,0
14,0	0,728	728,0	1373,6
15,0	0,844	844,0	1184,8
16,5	1, 025	1025,0	975,6
18,0	1,220	1220,0	819,7
19,5	1,405	1405,0	711,7
21,0	1,635	1635,0	611,6
22,5	1,850	1850,1	540,5
24,0	2,110	2110,0	473,9
25,5	2,390	2390,0	418,4
27,0	2,685	2685,0	372,4
28,0	2,910	2910,0	343,6
30,5	3,490	3490,0	286,5
32,0	3,845	3845,0	260,0
33,5	4,220	4220,0	237,0
37,0	5,015	5015,0	199,4
39,5	5,740	5740,0	174,2
42,0	6,535	6535,0	153,0
44,5	7,385	7385,0	135,4
47,5	8,430	8430,0	118,6
51,0	9,545	9545,0	104,8
56,0	11,650	11650,0	85,8

GOST 2688-80

Group B75

INTERSTATE STANDARD

DOUBLE ROLLER TYPE LK-R CONSTRUCTION 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

Date of introduction 1982-01-01

By the decree of the USSR State Committee for Standards of April 23, 1980 N 1833, the date of introduction was established 01.01.82

The term of validity was removed by the Resolution of the State Standard of 22.11.91 N 1752

REPLACE 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 linear tangency of wires in strands of the LK-R type with one organic core.

2. Ropes are classified according to characteristics

by appointment:

gruzoludskie - GL,

freight - G;

by mechanical properties of grades: VK, V, 1;

by the type of coating of the surface of the wires in the rope:

uncoated wire,

made of galvanized wire, depending on the surface density of zinc: C, F, OZh;

in the direction of the lay:

right,

left - L;

by combination of directions of rope elements lay:

cross,

one-sided - Oh,

combined - K;

by lay method:

non-expanding - H,

unwinding;

by manufacturing accuracy:

normal,

increased - T;

by the degree of balance:

flattened - P,

unaligned.

Legend examples

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

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

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

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

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


Diameter, mm					Estimated cross-sectional area of \u200b\u200ball wires, mm	Approximate weight of 1000 m of lubricated rope, kg	Marking group, N / mm (kgf / mm)
	wire
ka- nata	center- linen	first layer (inner)	second layer (outer)				Breaking force N, not less
	6 wire lock	36 wires	36 wire lock	36 wire lock			total of all wires in the rope	rope generally

Continuation

Notes:

1. Ropes, the breaking force of which is shown to the left of the bold line, are made of uncoated and galvanized wire. Ropes made of galvanized wire of groups Ж and ОЖ with diameters of 51.0 and 56.0 mm marking group 1370 N / mm (140 kgf / mm), 42.0-47.5 mm marking group 1470 N / mm (150 kgf / mm) , 30.5-47.5 mm of marking group 1570 N / mm (160 kgf / mm), 30.5-39.5 mm of 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 made by agreement between the manufacturer and the consumer.

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

2. Rope diameters over 10 mm are rounded to whole numbers or 0.5 mm.

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

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

Electronic text of the document
prepared by Kodeks JSC and verified by:
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Steel ropes. Range: Sat GOST. -
M .: Standartinform, 2011

Construction of buildings, bridges and roads, oil and gas processing and coal industries, sea and river shipping and other industries today cannot do without a steel cable. Flexible and durable ropes twisted from steel wire are used for lifting and moving various equipment, building materials, structural elements and other loads.

Features of the structure of the cable

A steel rope is a complex metal product that is the main element in many road-building, earthmoving, hoisting machines and mechanisms. Any cable consists of many wires twisted into strands, braiding a common core of metal or other materials.

The strength and construction of the rope depends on the number and thickness of wires in each strand, the number of cores and the material of their manufacture, the density and number of strands in the rope. The core of the twisted cable forms a model of the finished product and protects the surface of the rope from being squeezed under high mechanical loads. The metal core increases the structural strength of the cable, and reduces its structural elongation under tension and at high temperatures.

Rust control

The main problem with steel cables, corrosion, is solved in three ways:

The original wire is manufactured from stainless steel. The method is the most reliable and expensive.
Coating of wires with zinc or chrome. The most resistant spraying is designed for several years of operation.
Combined ropes with organic or synthetic core. Special grease impregnated cores made of hemp, sisal, beckoning or cotton minimize friction between the rope elements and prolong its life. Stronger and lighter double-layer core made of polyamide threads is used in cables for extreme sports equipment.

In terms of durability - quality - price, galvanized cables with non-metallic cores are considered the most optimal. Sometimes it is provided with a water-repellent lubricant (grease or nigrol).

Quality characteristics of steel wire rope

One of the main aspects of evaluating a steel wire rope is its strength. Determined by thickness, manufacturing method and design, the strength of the rope determines the permissible load on it. Working strength (allowable force) is determined by the maximum load at which the integrity of the cable is not violated for a long time. The tensile strength is determined by the minimum load that breaks the steel wire rope. Without collapsing, ropes made of steel with a thickness of 2 ... 10 mm can withstand a load of 47 to 174 kg. The minimum breaking load for steel ropes ranges from 235 kg for thin 2 mm ropes to 5880 kg for 10 mm diameter ropes.

Flexibility is an important criterion when choosing a cable. The more wires are twisted into a strand of steel rope, the more flexible it is. In cables of increased flexibility, each of 6 strands, braiding the organic core, is a twist of 144 wires. consists of 72 42 elements is considered rigid. In the production of steel ropes, wire with a thickness of 1 ... 8 mm is used.

Varieties of steel ropes

The rope classification is determined by the number of layouts:

With a single lay, the wire is wound in a spiral onto the core. Such a rope can be used both as a finished product and as an element of more complex cables.
For double stranding, ready-made single strands are used, wrapping around the core in a certain sequence. This technique is used for the production of single-layer and multi-layer cables. Special rules for wrapping allow double galvanized ropes (strands) not only to withstand significant loads, but also not to twist during operation.
The strongest and most reliable ropes are triple layed. For their formation, strands are produced according to a special method.

The direction of the strands during twisting can be either right or left.

Rope marking

The designation of the type of galvanized cable is determined by the type of weaving of the strands. Depending on the way the wires are arranged, the cables are divided into several types:

LK - linear tangency, at which the lay step in all layers is the same with a repeating pattern.
LK-O - when weaving a strand, a wire of the same diameter is used.
LK-R - the cable is formed by strands woven from wires with different diameters.
LK-RO - strands of different types are woven when making a rope.
TK - point contact of wires. With this weaving, each layer of the strand has its own step, and the layers intersect with each other.
TLK - a combined cable made of strands with both linear and point contact.

The correct choice of galvanized cable, depending on the operating conditions and its purpose, affects the durability and quality of the machines and mechanisms in which it is used. For example, the low density of the internal structure of TC types under dynamic load provokes strong friction of the rope layers and leads to its rapid wear.

The marking of the product also indicates the type of coating, diameter, type of lay, purpose, type of stranding, straightening, accuracy and strength.

The state standard defines the requirements for a galvanized cable, GOST has each type of steel rope. For example, steel cables of the LK-O type double lay with a metal core are produced in accordance with standard 3066-80, and with an organic one - 3069-80, LK-O single lay corresponds to standard 3062-80, LK-R cables with an organic core are produced in in accordance with GOST 2688-80 and so on. These documents regulate the purpose, mechanical properties of grades, types of wire coating, direction and method of lay, the combination of the directions of lay of its elements in the rope, manufacturing accuracy and degree of balance. Acceptance rules, technical requirements, marking, test methods, packaging, transportation and storage standards for cables are determined by GOST 3241-91.

Application of steel rope

Due to their reliability and practicality, galvanized steel wire ropes are actively used as a component of industrial equipment in a wide variety of areas:

in lifting and transport mechanisms;
in road construction, earthmoving and mining units;
in the technique of oil and gas industries;
in agricultural machines;
in shipbuilding and other industrial sectors.

A wide range of ropes of different diameters and strengths allows you to purchase the type of steel rope that matches your specific equipment.

According to their purpose, steel cables are divided into two groups: intended only for working with loads and for lifting or transporting both people and goods.

Advantages of galvanized ropes

Coating the steel wire with zinc increases the service life of the wire rope by 3 times and allows it to be used in corrosive environments. Galvanized ropes are characterized by a high level of corrosion resistance, which makes them suitable for use on river and sea vessels. Due to their high wear resistance, they are actively used in all areas of industry.

Zinc coating of steel wire divides ropes into three groups according to working conditions:

In a harsh aggressive environment.
In a particularly aggressive harsh environment.
In a moderately aggressive environment.

Sheathed rope

The modern industry offers a galvanized cable in a PVC braid, which increases protection against corrosion. Such ropes are successfully used when it is necessary to tie a load for immersion in a liquid, as guy wires when installing antennas and masts, during rigging and loading operations in adverse conditions and at low temperatures. Galvanized cable 3 mm in PVC sheath is used for overhead communication lines and power supply. Today, the range of galvanized ropes is being expanded with products coated with materials that can withstand high temperatures and resist combustion.

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