Steel wire ropes can be both strong and flexible. The key lies in the hierarchical twisting structure of "multiple wires in a strand, multiple strands in a rope", which transforms the rigidity of individual high-strength steel wires through the mechanical design of twisting into the overall flexibility. At the same time, it retains the tensile strength of the individual wires. Simply put, it is the dual effect of "dividing the force" and "flexible structure". The specific reasons can be broken down into two core points: 

1. Basic material: The high strength of a single steel wire is the essence of "strength". 

The stainless steel wires and carbon steel wires used to make steel cables are all high-strength metal wires that have undergone cold drawing treatment. They have extremely high tensile strength (for example, the common 1770MPa grade, which is far beyond that of ordinary steel). A single steel wire can withstand a considerable amount of tension, and the steel cable, which is formed by twisting together dozens or even hundreds of such high-strength steel wires, naturally possesses an extremely strong total load-bearing capacity. This is the core foundation of the "strength" of the steel cable.

2. Interwoven Structure: The hierarchical interweaving design is the key to achieving "softness", and it also enhances the "strength" characteristic.

The steel wire rope is not simply a bunch of steel wires placed side by side. Instead, it follows the multi-layer winding rule of "wires wound around strands, strands wound around cores", and each layer is wound in the opposite direction to the previous layer (alternating left-twist/right-twist). This design serves two purposes:

Achieving flexibility: When a single hard steel wire is twisted into strands, there is a small amount of movement space between the strands and between the wires. When the steel wire rope is subjected to bending force, each strand and each wire can slightly slide relative to each other, allowing the entire structure to flexibly bend and wrap, unlike a solid steel rod which is rigid. It is suitable for use scenarios such as pulleys and drums that require bending.  

Distributing the force to ensure "stability": When the steel wire rope is subjected to tension, the load is evenly distributed across each wire, preventing any single wire from being overloaded. This not only enhances the overall breaking strength but also avoids the situation where a single wire breaks directly leading to overall failure, making the high-strength characteristic more durable。