Wire Rope Cable and Considerations
Wire rope cable is essential in many industrial manufacturing applications. As wire rope constructions vary to suit manufacturing demands, choosing a wire rope purpose-built for your application is critical for project safety, efficiency and reliability. Understanding wire rope materials and construction is the first step to making a successful choice.
Understanding Wire Rope Constructions and Classifications
All wire rope cables, wire rope cable assemblies and cable lanyards are manufactured from individual wires, helically twisted around a central core for high load-bearing capacity. The most common wire rope constructions are 1×7, 1×19, 7×7 and 7×19, which represent the number of individual strands by the number of wires in each strand.
The 1x7 is the most common strand, including one straight center strand with six wires wrapped around it. This basic 1×7 independent wire rope core construction forms the foundation for many other cables, including the 7x7, 1x19 and 7x19. The 1×7 construction is the most rigid, while the 7×19 is one of the most pliable. SA Miniature Stainless Steel cables range from .009 to .045 inches. Our commercial-quality galvanized and stainless steel cables range from .032 to 1/4 inch in diameter.
For assistance in choosing the proper wire rope cable for your industry, read the following guide below:
- 1x7: The most commonly found strand in the use of mechanical cable. The strand is stiff compared to others and allows little give or stretch.
- 1x19: This option is more flexible and resistant than a 1x7. This configuration can be used across several applications as it's slightly more well-rounded.
- 7x7: A reliable choice for a wide range of uses. A 7x7 configuration is durable, flexible and can get used with a pulley system.
- 7x19: This option is by far the most durable and flexible cable. Additionally, this is the superior option for pulleys because it carries an excessive amount of weight.
Wire Rope Cable / Wire Rope Assemblies Construction Table
| Straight Tensile Load | Tensile Load With Flexing | Over Pulley | |
|---|---|---|---|
| Recommended Construction | 1x19 | 7x19 | 7x19 Coated and Lubricated |
| Minimum Construction | 1x7 | 7x7 | 7x7 |
The Most Common Types of Wire Rope
Aside from general wire rope classifications, several types of wire rope construction exist to accommodate a range of lifting applications, including:
- Swaged: A swager machine compacts or reduces this rope's diameter to improve crushing resistance and durability. This type of wire rope has many benefits but often has less bending fatigue resistance.
- Rotation resistant: As the name suggests, rotation-resistant rope is designed to resist rotation, spinning and twisting under load. Although it's helpful in single-line or multi-part systems, improper handling during reeling or installation can lead to uncontrolled rotation.
- Plastic coated: Plastic coating on the exterior surface of the rope provides additional protection against abrasion and environmental factors. Inspections can be challenging due to the layer covering the individual strands.
- Compacted strand: The strands in this type of wire rope are compacted with a die or rollers to reduce the rope's diameter. The compaction process flattens the outer wire surface and increases strand density, resulting in a stronger wire rope with extended surface life.
- Plastic impregnated: In this type of wire rope, the wire strands are impregnated with a plastic mix, filling the internal spaces between strands. This process improves bending fatigue and slows wear and tear, making the end product ideal for demanding lifting applications.
Wire Rope Cable Considerations
When selecting the appropriate wire rope cable for your wire rope assemblies or control product, there are a few factors which need to be considered:
CONSTRUCTURAL STRETCH:
All wire rope cables have spaces between each strand and wire. When a load is applied, the spaces between the wires are reduced and the wire rope cable will grow in length. The amount of the growth is determined by the load applied, length of the cable, and construction of the cable. Motion Control Technologies’ cable assemblies can be proofloaded (by applying a load of 60% of minimum cable breaking strength to the assembly) to eliminate any constructional stretch.
ELASTIC STRETCH:
The elastic stretch is an elongation of the cable wires when a load is applied. This can be a significant factor when the yield point of the wire is surpassed. Under this process, each strand of a mechanical cable gets longer as it experiences tension, and this correlates directly to the weight being added or pulled.
Ideally, the mechanical rope cable will give minimal elastic stretch for safety purposes. Our company takes the time to ensure products withstand the stress of job applications and sites. Please contact Motion Control Technologies to determine the elastic stretch of a specific cable.
MINIMUM BREAKING STRENGTH:
The minimum breaking strength of the cable is referred to as the minimum tensile strength. This is measured in pounds (lbs) or kilograms (kgs) and should be based on the maximum working load and safety factor. The recommended minimum safety factor ration is 10:1, representing the minimum breaking strength to the maximum working load.
Other factors to determine when engineering the correct cable for your requirements are CABLE DIAMETER,CABLE MATERIAL, and COATING ON THE CABLE.
| Flexibility | Tensile Strength | Stretch Resistance | Relative Cost | Corrosion Resistance | |
|---|---|---|---|---|---|
| Highest | 7x19 | 1x19 | 1x7 | 7x19 | Coated Stainless Steel |
| Medium-High | 7x7 | 1x7 | 1x19 | 7x7 | Bare Stainless Steel |
| Medium Low | 1x19 | 7x19 | 7x7 | 1x19 | Coated Galvanized Steel |
| Lowest | 1x7 | 7x7 | 7x19 | 1x7 | Galvanized Steel |
Cable Diameter
Larger cables contain a wider diameter because they are thicker and support more weight. Mechanical cable typically carries a diameter larger than 3/8-inch to withstand tension in multiple applications. Custom mechanical wire assemblies give your customers room to change the cable diameter to meet the needs of a project.
Wire Rope Cable Materials
We consider various materials when engineering wire rope cable for consumers. With each of our customers requiring different specifications from the next, Motion Control Technologies wants to learn as much as possible about expectations for our products before engineering. Our company incorporates both stainless and galvanized steel into wire rope cable assemblies, lanyards and more for their particular characteristics.
Three principal types of wire rope cable materials exist, including:
- Galvanized steel: Galvanizing steel involves coating carbon steel in zinc for better corrosion resistance. This material maintains its ductility for long periods and has higher breaking strength than many other cable materials, making it a popular choice in industrial and outdoor applications.
- Stainless steel: This metal alloy contains chromium, iron and other metals such as nickel. The most common grades include 302 and 304, providing high corrosion resistance. This material is ideal for marine industries.
- Coated: Depending on your application, you can choose from various coatings such as nylon, vinyl and plastic to provide additional flexibility and abrasion protection.
Stainless Steel Wire Rope Mechanical Assemblies
Using stainless steel in the mechanical cabling industry calls for positive results. Motion Control Technologies understands the demand for stainless steel as the material stands strong against corrosive environments.
Stainless steel can withstand extreme temperatures without experiencing damage, and it is easy to clean over extended use. Ultimately, our team can engineer the proper tools for our customers using this material thanks to its ability to get cut, molded and fabricated.
Galvanized Steel Wire Rope Mechanical Assemblies
Motion Control Technologies recommends using galvanized steel when corrosion factors are not the main concern. Galvanized steel acts as a powerhouse material for mechanical wire tether assembly, and it is extremely cost-effective for our customers. This material has a long life expectancy and offers a sense of reliability.
Wire Rope Cable Coating
Mechanical cable coating is often referred to as "jacket material". Adding plastic coatings to wire rope cable provides another layer of protection from stress and extreme conditions. Coated wire rope includes nylon and vinyl coating options that last against corrosion and everyday use, so contact Motion Control Technologies to help you decide the best solution.
How to Choose the Right Wire Rope for Your Application
The wrong wire rope choice can cost you time, money and safety. While selecting the ideal option can be complex, some basics to consider include:
- Working environment: The environmental conditions are one of the most critical considerations for wire rope cables. If you're selecting an option for an outdoor application, you'll need excellent corrosion-resistant materials.
- Flexibility: Consider how much bend your application requires and ensure you discuss your flexibility requirements with your provider. As a general rule, the more strands, the more flexibility.
- Crush resistance: Balancing flexibility and crush resistance is crucial. Ensure you choose an option that meets both criteria for your specific use case.
- Breaking strength: Above all, your wire rope must be able to carry the intended load. Only subject it to at most 50% of its total breaking load.
Engineer the Perfect Wire Rope Cable Assembly With Motion Control Technologies
Wire rope cables are complex equipment, and choosing the right option for your application is essential to overall project success. Original equipment manufacturers (OEMs) and distributors have relied on us for high-quality mechanical components and custom solutions.
With over 30 years of experience in the wire and cable industry, we pride ourselves on delivering engineering expertise and quality customer service to every client. We take the time to work with you to find the ideal components to make your projects safer and more efficient. Please speak to an expert today to learn more about our mechanical cable solutions.
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