Wire rope is a rope made of multiple steel wires twisted according to certain rules. Widely used in mining, oil, ports, forestry, shipping, construction, lifting machinery, transportation, etc. Compared with other ropes with similar functions, steel wire rope has the advantages of high strength, good toughness, no noise and convenient use. The commonly used steel grades for rope making are 60, 65, 70, 75MnCuTi, etc., and the sulfur and phosphorus content shall not exceed 0.035.

1. Classification

According to the contact state of the adjacent layer steel wire in the strand, the steel wire rope can be divided into three basic structural forms: point contact steel wire rope, line contact steel wire rope and surface contact steel wire rope.

Point contact: there is point contact between adjacent layers of steel wires in the strand. Except for the central steel wire, the diameters of each layer of steel wires are equal, and the strands are formed by layered twisting.

Line contact: In the form of linear contact between adjacent layers of steel wires in the strand, the strand is made of steel wires of different diameters at one time.

Surface contact: the form of surface contact between adjacent layers of steel wires in the strand.

Point and line contact steel wire rope: there are two contact forms of point and line between adjacent layers of steel wire in the strand. The strands are made of steel wires of different diameters twisted in times.

According to the form of the strand section, the wire rope can be divided into round strand wire rope and special-shaped strand wire rope (the special-shaped strand wire rope mainly includes triangular strand wire rope, elliptical strand wire rope and fan-shaped strand wire rope).

Special-shaped strand wire rope: Special-shaped strand wire rope is named after its strand section is triangular, oval or fan-shaped.

According to the surface state of steel wire (wire rope), steel wire rope can be divided into smooth steel wire rope, galvanized (zinc aluminum alloy) steel wire rope and coated (package) plastic steel wire rope.

Plain steel wire rope: also called ordinary steel wire rope, by the surface is not galvanized smooth steel wire twist. At present, the steel ropes produced in various countries in the world are divided into about 50 kinds according to their structures, such as 6 × 19. 6 × 37, 6 × 25F, 6 × 29F, 8 × 19W, 6V × 37, 6Q × 33 6V × 21, etc. Example: 6 × 37: It means that the rope has 6 strands, each share has 37 monofilaments; 8 × 19W: It means that there are 8 strands, each of which consists of 19 steel wires, which are twisted by Wallingtun.

Most of the wire rope has a core in the center, which is used to remove rust from oil and reduce friction between strands. The smooth steel wire rope is widely used and is often used in machinery, construction, forestry, mines, etc.

Galvanized steel wire rope: made of galvanized steel wire. Commonly used in corrosive medium work equipment such as: ships, fisheries, etc.

Coated (wrapped) plastic wire rope, including aviation wire rope, multi-strand wire rope, single-strand wire rope, triangular-strand wire rope, elevator wire rope, tape wire rope, rubber hose wire rope, sealing wire rope, salt well wire rope, elliptical strand wire rope, flat strand wire rope, surface contact wire rope, special-strand wire rope, etc. Most of these wire ropes are used for special equipment, and their structure has certain characteristics. Carefully check the relevant standards when ordering or selecting.

Points by intensity:

That is, according to the nominal strength of the single wire, the wire rope is divided into several levels. The grading criteria vary from country to country. For example, China divides round strand and special strand wire ropes into 1570, 1670, 1770, 1870 and 1960(N/mm2), while Japan divides round strand wire ropes into e (1320 N/mm2 grade), g (1470 N/mm2 grade), a (1620 N/mm2 grade) and B (1770 N/mm2 grade), the EU standard is to divide the round strand steel rope into three categories: 1770, 1960 and 2160(N/mm2).

2. Twist direction

The so-called wire rope (or strand) twist direction, refers to the strand in the rope (or wire in the strand) twisted spiral direction. Judgment method: Place the rope (or strand) vertically and observe. If the spiral rising direction of the strand (filament) rises from left to right in a "Z" shape, it is called right twist. The one that rises from right to left in an "S" shape is called left twist.

The same twist direction of the strand and the rope is called the same twist or the forward twist, and the different twist direction of the strand and the rope is called the alternating twist or the reverse twist. According to the direction of strand and rope twisting, steel wire ropes are divided into left alternating twist, right alternating twist, right same twist and left same twist. Compared with alternating twisting, the same-direction twisting rope has a flat surface, large contact area with the rope wheel, slow wear, long life, but large rotation tendency. According to the number of strands of the steel wire rope, the number of steel wires in the strands, and whether there is a fiber core or metal core in the rope or strands, the steel wire rope has different structures.

a Right alternating twist steel wire rope: the rope is twisted right and the strand is twisted left

B left alternating twist steel wire rope: the rope is left twisted, and the strand is right twisted

c Right-hand twisted wire rope in the same direction: rope right-hand twisted, strand right-hand twisted

d left twisted wire rope in the same direction: rope left twisted, strand left twisted

e right mixed twist steel wire rope: rope right twist, part of the left twist, part of the right twist

f left mixed twisted steel wire rope: the rope is left twisted, some strands are right twisted, and some strands are left twisted

Right twist (Z), left twist (S), alternating right twist (SZ), alternating left twist (ZS), same right twist (ZZ), same left twist (SS).

Wire rope core and code

a Fiber core (natural or synthetic):FC

B Natural fiber core: NF

c Synthetic fiber core: SF

d Metal wire rope core: IWR (or IWRC)

e wire strand core: IWS