Wire ropes consist of multiple strands of metal wire—typically steel—twisted together into a laid rope pattern with a diameter—i.e., gauge—of greater than 3/8 inch. While composite ropes with smaller gauges are referred to as cables or cords, ones with larger gauges that employ several strands of laid rope twisted together—i.e., a cable laid pattern—are known as large gauge wire rope.
There is a wide range of wire ropes available, each of which demonstrates unique characteristics that make it suitable for a specific purpose or application. The following blog post outlines the types available and some of the selection considerations to keep in mind when choosing one for a project.
Types of Wire Rope
Wire rope comes in many different forms, with the suitability of each depending on the particular application. Some of the types of wire rope commonly employed include:
Rotation-resistant wire rope
This type of wire rope is designed to stabilize loads during lifting operations by preventing rotation, spinning, and twisting. It can be used in a single line or a multi-part system and is often employed in applications where it doesn’t make sense or is impossible to use a tag line, increase sheave sizes, or relocate the dead end of a rope. When using rotation-resistant wire rope, care should be taken when securing the rope ends or attaching fittings to ensure they don’t unlay or kink.
Compacted strand wire rope
During its manufacture, the strands of this type of wire rope are compacted by a die or rollers. The compacted strands have a smaller outer diameter and a smoother outer surface and demonstrate greater strength and wear resistance than comparable uncompacted strands. Compacted strand wire rope is commonly used on ship and harbor mobile cranes, container bridge cranes, overhead hoists, and more.
Compacted and swaged wire rope
Compacted and swaged wire rope differs from the above in that the machine operators run the wire rope through only once it is closed. The strands used in its manufacture can be round or compacted. The advantage of using this type of wire rope is higher strength and wear and crushing resistance.
Plastic coated wire rope
The application of a plastic coating to a wire rope increases the rope’s resistance to abrasion, wear, and other environmental stresses. However, the coating also decreases the ease to which it can be inspected for repair and replacement. This type of wire rope is often used for high strength applications, such as washing lines, cable locks, and barrier ropes.
Plastic impregnated (PI) wire rope
This type of wire rope is reinforced by filling the spaces between the strands with plastic. The addition of plastic reduces internal wear and tear and helps make these ropes suitable for heavy lifting.
Plastic coated/filled independent wire rope core (IWRC) wire rope
The core of this type of rope is either filled or coated with plastic to improve resistance to bending fatigue and general wear and tear.
Wire Rope Selection Considerations
When choosing a wire rope, there are several considerations to keep in mind, including:
- Environment: Consider the environmental conditions of the application—e.g., is it sunny, wet, hot, or cold? If water is present and will come into contact with the rope, choosing a corrosion resistant material such as stainless steel is wise.
- Flexibility: If the applications require the wire rope to bend around an object, choose one that demonstrates sufficient flexibility. A rope that has more strands exhibits greater flexibility than one with fewer strands.
- Crush resistance: Although wire rope with a fiber core offers the most flexibility, it also demonstrates less resistance to crushing. If crushing is not a concern but flexibility is, fiber core wire rope is ideal.
- Breaking strength: The breaking strength of a wire rope dictates how heavy of a load it can carry. When lifting something overhead, industry professionals suggest using a wire rope that has a breaking strength of 5 to 1 of the total load (e.g., a 500-pound breaking strength for a load of 100 pounds).
Wire Rope Solutions From Armstrong / Alar
Industry professionals employ wire rope in a wide range of applications. Choosing the right type of wire rope requires careful consideration of the requirements and restrictions of the application, including the environment and total load.
If you need selection assistance, turn to Armstrong Alar. With almost three decades of experience working with wire rope, we have the skills and knowledge to help you find the optimal wire rope for your project. Learn more about wire rope on our wire rope page or contact us today with specific questions.