The four twist directions of steel wire rope have their own characteristics, in which the right alternating twist (ZS) strand is right twisted and the rope is left twisted. When stressed, the twist direction of the strand is opposite to that of the rope, which has good anti-rotation performance. It is often used in the lifting mechanism of tower crane in construction site to ensure the stability of lifting. Left-hand twist (SZ) strand is twisted left and rope is twisted right, which is similar to right-hand twist and adapts to two-way stress, such as port crane loading and unloading. Right-hand twisted (ZZ) strands and ropes are both twisted right, and the steel wire has close contact and good flexibility, which is suitable for occasions with small bending radius such as small hoisting equipment, but it is often necessary to equip with anti-rotation devices to resist poor rotation. Left-hand-twisted (SS) strands are all twisted left, which has excellent flexibility. It is mostly used in scenes that require high softness, such as hand weaving, and also has weak anti-rotation, so it should be handled accordingly.
