Steel wire rope and its common standards

1. Overview

(1) Definition: the prepared steel wire is twisted into a single strand rope on the machine according to the regulations, and then 6 or 8 such strands are combined with fiber core, and the re synthesized rope is called steel wire rope.

(2) Types and uses: there are many classification methods of steel wire rope, and the classification methods are different in different countries. The common ones are classified according to the structure, twist direction, surface, use and strength of steel wire rope. The diversity of varieties reflects the diversity of uses.

① According to the twist direction, there are right twist (z), left twist (s), alternating right twist (SZ), alternating left twist (ZS), same right twist (zz) and same left twist (SS). ② According to the surface, there are two types: smooth and galvanized. ③ Classification by strength: the steel wire rope is divided into several grades according to the nominal strength of monofilament. Different countries have different grading standards. For example, China divides round strand and special-shaped strand wire ropes into 140, 155, 170, 185 and 200 (kg / mm2), while Japan divides round strand wire ropes into 135, 150, 165 and 180 (kg / mm2), while Germany divides round strand wire ropes into 140, 160, 180 and 200 (kg / mm2). ④ Classification by structure: the basic idea of this classification is to achieve classification by directly showing the internal structure of the steel rope. The specific format is expressed by the combination of integers, letters and symbols in the specified order. It can classify all existing round strands, special strands and closed wire ropes. At present, there are about 50 kinds of steel ropes produced in the world, i.e. 6 ××× Fi(25)、8 × W(19)、7 × 7+6 × Fi(29)、6△ × (36), 6 = (33) + 6 △ (21) and other categories. Example: 6 × 37: the rope has 6 strands, with 37 monofilaments per share; eight × W (19): it means that there are 8 shares, 19 filaments per share, which are made by Wallington. See relevant standards provided in "7. Common standards" in this section. ⑤ According to the purpose: A. pulling: steel rope for tugboat, floating transportation, cargo net, etc; b. Bearing: steel rope for lifting, bridge and cableway; c. Lifting: steel rope for elevator, mine, cable car, etc; d. Fixing: steel rope for positioning of wharf and high-voltage pole (tower); e. Special purpose: petroleum, chemical, aircraft and other special steel ropes.

2. Main production plants and countries and regions to be exported

(1) It is mainly produced by wire rope factories in Tianjin, Shanghai, Shenyang, Shaanxi, Jiangsu and other places. Its products are not only supplied for domestic use, but also exported to the Philippines, Singapore, Hong Kong, Spain, Canada, Egypt, Yemen, etc.

(2) China's imported steel wire rope mainly comes from Germany, Japan, Britain, Russia, South Korea, etc.

3. Specification and appearance quality

(1) Specification: indicates the size, structure, strength, etc. of the steel rope. Due to the different models and customs of steel wire rope produced in various countries, the format of specification is also different. Tables 6-7-31 and 6-7-32 are the specifications of round strand steel wire rope in China and Germany [(2) and (19) in "7. Common standards].

Table 6-7-31 specification format of round strand wire rope in China

Diameter: total sectional area of steel wire reference weight: nominal tensile strength of steel wire rope (kg / mm2)

Steel wire rope: steel wire 140 155 170 185 200

Total breaking force of steel wire

Mm mm2 kg / 100M kg, not less than

Table 6-7-32 specification format of German round strand wire rope

Nominal diameter of steel wire rope (weight per unit length) (g)

Kg / M theoretical calculation of breaking force and minimum breaking force

When the nominal strength of steel wire is the following value:

1570N/mm2

(160kgf/mm2) 1770N/mm2

(180kgf/mm2) 1570N/mm2

(160kgf/mm2) 1770N/mm2

(180kgf/mm2)

F theoretical value f theoretical value f min f min

D) allowable deviation (%): kn KGF kn KGF kn KGF kn KGF

(2) Appearance quality: the appearance of the steel wire rope, whether galvanized or not, shall be smooth, without fracture, even twisting, and loose ends; The surface of monofilament shall be free of defects such as depression, rust, flattening and bruise.

For smooth steel wire rope, the surface shall be coated with oil in order to prevent corrosion and rust.

4. Chemical composition and inspection

(1) Monofilament: generally, the chemical composition is not specified, because the various specifications and grades of wire rod originally used for the production of steel wire have been tested for chemical composition and meet the standards.

(2) Galvanized wire: the single wire of galvanized steel wire rope, which specifies the weight of zinc layer, the number and time of copper sulfate test, and indicates the implementation standard. For example, in GB / t8918-1996, the galvanized monofilament with diameter ＞～ shall be subject to the provisions of table 6-7-33 and the test methods of gb2973-91, gb2972-91 and gb2973-91 respectively.

The Japanese standard jisg3525 only specifies the weight of the zinc layer, and the requirements listed in table 6-7-34 and jish0401 test method shall be followed for the diameter to zinc wire. 

Table 6-7-33 inspection regulations for single wire of galvanized wire rope with diameter ＞～

Steel wire diameter (mm), galvanized layer group, immersion times, each immersion time (s), galvanized layer weight (g / m2)

> ~ a 1 60 66

B (1) 30

Table 6-7-34 minimum zinc coating amount (g / m2) required by Japan for zinc steel wire with diameter between ~ and

Monofilament diameter (mm) galvanizing amount

Class G (Class A)

Over, less than 60 50

Over, less than 70 60

5. Physical performance inspection

(1) Mechanical index

① Total breaking force: refers to the breaking force of the whole rope, which is divided into three types: a Theoretically calculated breaking force (FR): equal to the real cross-sectional area GM of the steel wire rope and the nominal strength of the steel wire σ Product of 2: FR = GM σ 2； b. Measured breaking force (FE): equal to the sum of measured breaking forces of all monofilaments in the rope: Fe = ∑ f; c. Actual breaking force (FW): equal to the force when the whole rope is actually broken.

FR is listed in national standards, and Fe or FW or both are obtained during inspection. This is an important mechanical index.

② Monofilament tensile strength: generally refers to the nominal strength, which is one of the important bases for determining the actual mechanical characteristics of the whole rope. The difference between the measured strength and the nominal strength of monofilament is clearly defined in national standards and strictly controlled. For example, the German standard only allows a certain range of positive deviation, see "7. Common standards" (19).

③ The torsion, repeated bending, winding or knotting of monofilament are all indicators of plasticity and toughness. It plays an important role in ensuring the mechanical properties of the whole rope, and the general standards have provisions.

Attention should be paid to the above mechanical indexes. The inspection items specified in the standards of various countries are different. For example, the requirements for monofilament in China and Germany include: strength, torsion and repeated bending (knot); The Japanese standard stipulates strength, torsion and winding.

Secondly, for monofilaments of the same size and strength level, the mechanical indexes of smooth surface and galvanizing are different. For example, see "7. Normal standard" (2) for Chinese standards.

Table 6-7-35 and table 6-7-36 respectively show the provisions on single line torsion and repeated bending within the partial diameter range in the Chinese and German standards [(2) (19) of "7. Common standards".

Table 6-7-35 mechanical properties of smooth steel wire in China

Steel wire diameter (mm), nominal tensile strength (kg / mm2), 180 degree bending, 360 degree torsion

Bending arc radius (mm): repeated bending times of each steel wire; torsion times of each steel wire

Special I II special I II

Not less than not less than

140 10 7 6 4 19 14 9

155 6 5 3 17 12 7

170 5 4 2 15 10 5

140 8 7 5 20 15 10

155 7 6 4 18 13 8

170 6 5 3 16 11 6

Table 6-7-36 mechanical properties of German smooth and galvanized steel wire

Steel wire diameter (mm) bending cylinder diameter (mm) minimum bending times of steel wire with the following nominal strength n / mm2 test length

L minimum number of torsion of steel wire with the following nominal strength (n / mm2)

1570 1770 1570 1770

10 9 200xd 58 54

8 8

7 6

13 12

11 10

9 8

(2) All mechanical indexes are inspected according to the test methods listed in the standards. See "7. Common standards".

6. Packaging

Generally, each wire rope shall be packed separately. There are the following types: packaging with protective materials (for special large-size steel rope); Iron drum packaging; Linen or other equivalent materials; I-wheel (wood, steel, plastic or its combination) packaging, etc.

7. Common standards

(1) GB / t352-88 sealed steel wire rope

(2) Steel wire rope (GB / t8918-1996)

(3) Gb2104-88 general provisions for packing, marking and quality certificate of steel wire rope

(4) Yb / t5197-93 aviation steel wire rope

(5) Gb8903-88 steel wire rope for elevator

(6) GB / t5224-1995 steel strand for prestressed concrete

(7) Yb / t5004-93 galvanized steel strand

(8) GB / t16269-1996 surface contact wire rope

(9) Yb / t5225-93 thick diameter steel wire rope

(10) Yb / t098-1997 galvanized steel strand for optical cable

(11) GB / t14451-93 wire rope for control

(12) Sn / t0611-1996 inspection regulations for export steel wire rope

(13) Astma416-96 steel strand for prestressed concrete

(14) Din21251 / 1-84 round strand wire rope for lifting

(15) Jisg3525-95 steel wire rope

(16) Jisg3535-95 steel wire rope for aviation

(17) Jisg3540-95 operating wire rope

(18) Bs302 / 1-87 general specification for multi strand wire rope

(19) Din3051-3071-72 steel wire rope