18*7+FC 18*7+IWS Rotation Resistance Steel Wire Rope
Rotation-resistant ropes and low torque (low rotation) ropes
Rotation-resistant ropes are ropes (mostly multilayer ones) in which balance of the torques is achieved.
There are two constructive ways to achieve balance conditions for steel ropes:
1st way – due to contra-lay of the rope layers;
2nd way – due to ordinary lay in a ropes with up to 4 strands
Multi-strand ropes with at least 3 layers of strands laid around the core having at least 15 strands in outer layer can be considered rotation-resistant ones.
Moreover, the outer strands should have the opposite direction of the lay, comparing to the strands of the inner layers of the rope. Such ropes have a very low torque or do not have it at all in a certain range of loads. They may be used with one free end, with or without a swivel.
Low-torque (low-rotation) ropes include ropes with more than ten outer strands and having at least two layers of the strands laid around the core with an outer layer of strands laid in the opposite direction comparing to inner layers. They have a significant torsional resistance. But in order to have a stable operation, they are not recommended to be used with one free end and with a swivel.
Special approach to handling of such ropes is requires due to complexity of their construction.
Do NOT use class 18×7, 17×7, or 24×7 wire rope attached to a swivel or have one or both rope ends rotate freely under load. Doing so will result in a loss of rope strength of between 30% to 40%.
Block Twisting (Cabling) will occur when used exceeding certain lifting heights. This is NOT a non-rotating rope.
Model Number: 18*7+FC 18*7+IWS
18×7 ropes are ROTATION RESISTANT but NOT non-rotating
Usage: Vertical Shafts/Oil drilling/Ship loading
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Cautions:
1. When choosing wire rope should consider the safety factor, even if no broken, lifetime of the rope will be shortened. To load object, safety factor should be not less than 4:1, to load human, it must be more than 10:1.
2. Method of putting wire rope is the key before using, the right method can eliminate the stress inside the rope.
3. Never use wire rope overload.
4. Don’t make the wire rope touch the sharp corner when strapping or lifting, consider to use protector if need.
4. Multiple strands wire rope should be fixed when cut, prevent outer layer loose.
5. It should be scrapped when abrasion on outer layer, corrosion degree or broken wires exceed the specified value.
Wire Rod—Pickling&Surface treatment—Drawing—Patenting—Plating—Stranding&Closing
