Crane wire ropes are core components in lifting machinery, responsible for lifting, traction, and load-bearing tasks. Common standards include GB/T 20118, YB/T5359, ISO2408, EN12385-4 etc. Crane wire ropes possess high tensile strength, excellent fatigue resistance, and good flexibility, making them suitable for complex working conditions involving frequent bending and high impact loads.
Common diameter range: 6~60mm
Common rope construction: 6×36WS, 8×K26WS, 4×V39FC-FC, 18×7-WSC, 35(W)×K7 etc.
Core type: Fiber core (FC), Independent wire rope core (IWRC) etc.
Wire finish: Bright, galvanized, plastic coated etc., suitable for different corrosive environments
Strength range: 1770–2160 MPa
Cross laid: low cost, suitable for light load binding, good flexibility, poor wear resistance, like 6×37M-SFC
Parallel laid: such as Seale (S) and Warington type (W), low contact stress, long service life, like 6×19S-SFC
Compacted: high steel wire tensile strength, commonly used in lifting equipment with large tonnage loads. like 8×K26WS-IWRC
Fiber core (FC): the rope core has better oil storage performance and the steel wire rope has better flexibility.
Steel core (IWRC): high temperature resistant and compression resistant, commonly used in lifting equipment with heavy loads.
Single-strand steel wire rope: generally, there is only one layer of strands around the rope core. RHRL is commonly used. Anti-rotation performance is generally average, such as 6×19S and 8×K19S.
Multi-layer steel wire rope: generally, there are at least two layers of strands around the rope core, with adjacent layers having opposite lay directions. It has better anti-rotation performance, such as 18×7-WSC and 35(W)×7.
Main hoisting rope: It is recommended to use steel wire ropes with parallel laid wire + steel core + anti-rotation construction, such as 35(W)×7, commonly used in tower cranes, crawler cranes, mobile cranes etc.
For main hoisting wire ropes that require repeated bending and pass through multiple pulleys in the hoisting structure, it is recommended to use steel wire ropes with parallel laid wire/compacted wire + fiber core/steel core + single-layer construction, such as 6×36WS-SFC, 6×36WS-IWRC, and 8×K26WS-IWRC, commonly used in port container cranes.
Luffing structure and trolley system: It is recommended to use steel wire ropes with cross laid wire/parallel laid wire + fiber core + single-layer construction, which offer better bending performance, such as 6×19M-SFC and 6×19S-SFC.
Working environment: For outdoor work, galvanized work or heavy lubricating work is preferred. For indoor operations, non-galvanized work can be used to reduce costs.
Steel wire ropes have a limited service lift and must be inspected regularly and replaced on time. When a steel wire rope shows the following problems, it must be replaced immediately.
Excessive wire break: within one lay length, the number of broken wires reaches 10% of the total number of wires (for RHRL). If lifting dangerous goods or hot metal, this standard is halved to 5%.
Diameter over reduction: when the diameter of a steel wire rope decreases by 7% or more relative to its nominal diameter due to wear or core breakage, it must be replaced.
Structural deformation: cage-like distortion (like a birdcage bursting open), strand extrusion, kinking, local flattening, or severe wavy deformation occurs.
Severe corrosion: deep pits appear on the surface, the steel wires loosen, or internal corrosion causes the steel wire rope to lose its elasticity.