- May 09, 2025
- News
Comparison of Sling Types: Wire Rope and Chain
Explore the key differences between wire rope and chain slings in our comprehensive comparison. Understand their strengths, applications, and safety considerations to choose the right lifting solution for your needs.
Selecting the right lifting sling is crucial for any heavy-duty rigging or overhead lifting operation. Wire rope slings and chain slings are two of the most common metal slings used in industrial rigging and crane work. Each has specific strengths, limitations, and ideal use cases. This article compares wire rope and chain slings in terms of use cases, load capacity, flexibility, durability, maintenance needs, cost-effectiveness, environmental suitability, and safety. Hopefully, this will help you choose the type of sling best suited to your lifting task.
Features and Uses of Wire Rope Slings
Wire rope slings are made of multiple steel wires laid in strands around a core. This construction (often with a fiber or steel core) gives them strength, flexibility, and resistance to bending stresses. Steel wire rope comes in various configurations (e.g. 6×19, 6×37 strand constructions) that balance abrasion resistance and flexibility. Wire rope slings are widely used in construction, manufacturing, shipping, and material handling industries. They are popular in environments like steel mills, foundries, and fabrication shops where heavy loads and harsh conditions are common.
1. Applications and Advantages
Wire rope slings excel in heavy-duty lifting and general-purpose rigging. They are suitable for overhead cranes, hoists, and load-securing hardware on cranes. Typical use cases include lifting steel beams, concrete blocks, machinery, and structural elements. Compared to chain slings, wire rope slings generally offer:
- High strength-to-size ratio: Wire rope can lift large loads relative to its diameter, providing a high working load limit (WLL) without excessive bulk.
- Lower cost per lift: Wire rope slings usually have a lower initial cost per ton of capacity than equivalent chain slings.
- Flexibility in hitching: Braided wire rope conforms to the load in choker, vertical, or basket hitches. Its snug fit in a choker hitch helps secure loads tightly.
- Hardware reusability: If a wire rope sling is cut or damaged, the end fittings (master links, hooks, shackles) can often be reused if they are undamaged.
- Abrasion resistance: Steel strands provide good resistance to abrasion and wear, especially with more wires in the rope construction. This helps the sling last under rough surfaces.
- Design Factor: Wire rope slings are often rated with a 5:1 safety factor (per ASME B30.9), meaning breaking strength is five times the rated WLL. This built-in margin accounts for wear and unforeseen stresses.
For example, a 6×19 wire rope sling balances strength and abrasion resistance, making it suited for most general lifts. Manufacturers note that wire rope is "lightweight and economical for the amount of load it can carry".
2. Limitations and Maintenance
Despite their strengths, wire rope slings have some limitations and maintenance needs:
- Inspection difficulty: The internal strands and core can hide damage. It is hard to inspect for internal wear or corrosion, especially around the core.
- Corrosion and broken wires: Wire rope is susceptible to rust and broken wires if not properly maintained. Moisture or chemicals can corrode strands, so regular lubrication and corrosion-resistant materials are important.
- Kinking and crushing: Wire rope can permanently kink or crush if bent around too small a radius or sharply dragged. Such abuse weakens the rope and can require immediate removal from service. Operators must avoid wrapping rope around loads with tight corners to prevent kinks.
- Lower strength-to-weight than chain: Although wire rope is strong, it has a lower strength-per-weight compared to alloy chain slings. For extremely heavy loads, chain can achieve higher capacity in a similar size.
- Temperature limits: Most steel wire ropes are limited to about 400 °F (204 °C) maximum and –40 °F (–40 °C) minimum, beyond which properties can degrade.
- Non-repairable: A damaged wire rope sling must be retired. Wire rope itself cannot be repaired if it fails inspection; the entire sling is taken out of service.
- Weight: While lighter than chain of the same WLL, wire rope slings can still be heavy for very large capacities.
Maintenance: Wire rope slings require regular care. Keep them clean and well-lubricated to protect the strands and core. Lubrication penetrates between wires to reduce friction and shield against moisture. Inspect slings often: look for broken wires, corrosion, rust, or kinks. ASME standards allow a few broken wires, but extensive broken strands mean the sling must be removed. Avoid shock loads and sharp edges; use padding or corner protectors when lifting loads with edges to prevent slicing the rope. Well-maintained wire rope slings can have long service lives, but replacing wire rope assemblies is part of routine fleet management.
Features and Uses of Chain Slings
Chain slings are made of high-grade alloy steel links (commonly Grade 80 or Grade 100) rated for lifting. They consist of a series of welded metal links forming a loop or legs, with end fittings like hooks or master links. Alloy chain slings are extremely durable and rugged. They are designed for heavy-duty overhead lifting, especially in harsh or high-heat environments. They work well for overhead lifts in construction and heavy manufacturing too. Their design gives you flexibility on the hook while keeping the load secure. With chain slings, you get a tool that handles heavy loads day in and day out without failing.
1. Applications
Chain slings are known for their toughness and versatility. Typical use cases include:
- Lifting hot materials (e.g., forged parts, molten steel billets) or abrasive loads that would damage other slings.
- Complex or irregular shapes: Chain can wrap around corners more easily than wire rope, making it suitable for odd-shaped loads.
- Multi-leg assemblies: Chains can be built in 2-leg, 3-leg, or 4-leg slings with different lengths and hooks, allowing balance of irregular loads.
- Extreme loads: Chain slings are used where the capacity required is extremely high. Each size chain has a very high Working Load Limit (WLL).
2. Key Strengths of Chain Slings
- Very high capacity: Due to high-strength alloy steel, chain slings can lift "extremely heavy loads". A single leg can handle tens of thousands of pounds, and multiple legs multiply the capacity.
- Durability: Chain slings withstand rough handling, abrasive surfaces, and impact better than other sling types. They are "absolute workhorses" in rugged environments.
- Heat resistance: Alloy chain retains strength at high temperatures. It is "perfect for high-temperature applications", unlike synthetic slings that melt and wire rope that may lose some strength.
- Flexibility: Although stiff as metal, chain links can articulate fully. Chain slings are "very flexible" and can handle corners with ease. This makes lifting around corners or edges smoother.
- Repairability: If a link or fitting fails, a chain sling can often be repaired. Damaged links or hooks can be replaced, and the sling retested and recertified.
- Versatility: Chains come in various grades and sizes. They can be made into custom lengths and configurations. Grade 100 or 80 chain offers very high strength in a given link size.
For example, an Alloy Grade 100 chain sling may have a design factor of 4 or 5 (some manufacturers rate 5:1), meaning its break strength is four to five times its WLL. Chains do not stretch under load; any permanent elongation is a sign of overload or damage. As a chain wears, its effective diameter decreases, and once the wear exceeds about 15% of its original thickness, the corresponding links should be removed.
3. Limitations and Maintenance
Chain slings come with some drawbacks:
- Weight: Chain slings are heavy. Larger chains (for high WLL) add significant weight to rigging, making them more difficult to move by hand.
- Cost: Alloy chain is expensive. The initial cost per foot of chain is higher than wire rope of similar capacity.
- Inspection time: Chains require careful visual inspections. Each link and fitting must be checked for distortion, cracks, wear, and proper tagging. This can be time-consuming compared to inspecting wire rope.
- Risk to load: Being metal, chain slings can scratch or dent sensitive surfaces. They are not suitable for fragile or delicate loads without padding.
- Corrosion: Carbon steel chains rust if exposed to moisture and not lubricated or coated. In corrosive environments, stainless or properly coated chain should be used.
- Rigid failure: When chain does fail, it can break suddenly (unlike wire rope which shows gradual failure). A broken chain link can recoil violently, so detecting wear early is critical.
Maintenance: Chain slings should be cleaned and lubricated periodically to prevent corrosion and ensure flexibility. Inspect chain slings before each use and at regular intervals. A good practice is daily or weekly visual checks plus an annual formal inspection. Inspectors should look for:
- Wear and thinning: Measure link diameter in multiple places. If any link has worn more than ~15%, remove the sling.
- Deformation: Bent, twisted, or elongated links or connectors are not safe. Even small distortions weaken the chain.
- Cracks and nicks: Any cracks or gouges on links mean immediate removal.
- Stretch: If a chain can be pulled out of its normal length, it has been overstressed. Replace the sling if it no longer returns to its original shape.
- Corrosion: Rust can hide damage. Clean rust and apply lubricant or anti-seize as recommended.
- Tag integrity: The identification tag must be readable with WLL and manufacturer information.
- Lubrication: A light film of oil keeps links moving freely and repels moisture.
After inspecting and maintaining, store chain slings in a dry, sheltered area to prevent rust. Worn or damaged chains must be taken out of service to avoid accidents.
Key Differences Between Wire Rope and Chain Slings
1. Load Capacity and Strength
Both wire rope and chain slings can carry heavy loads, but chain slings generally support higher capacities in a given size. High-grade alloy chain is extremely strong: chain links in Grade 80 or 100 alloys can lift very heavy items and resist cutting or abrasion by sharp loads. Chain slings are often used for the heaviest lifts, and they do not elongate under proper loading. In contrast, wire rope slings are also very strong for their weight, but steel wire has a lower strength-to-weight ratio than alloy chain.
Each sling is rated by its Working Load Limit (WLL) and a safety (design) factor. Design factors differ: wire rope slings typically use a 5:1 factor (breaking strength is 5× WLL), whereas alloy chain slings use at least 4:1. This means wire rope is built with a slightly higher safety margin. For example, a wire rope sling with 10,000 lb WLL has a minimum break strength of ~50,000 lb, while a chain sling of 10,000 lb WLL breaks at ~40,000 lb (using 4:1). Despite the higher safety factor, chain's absolute capacity per inch of material often exceeds that of wire rope. The choice often comes down to required capacity and available equipment.
2. Flexibility and Configuration
Chain slings are more flexible around corners. Each link pivots, allowing the chain to bend in multiple directions. This flexibility makes chain better for loads with irregular shapes or sharp edges. Wire rope, while flexible along its length, does not bend as freely around tight radii. An independent wire rope core (IWRC) is even stiffer than a fiber core. Wrapping wire rope around a very tight corner can permanently deform (kink) it.
Both slings can be configured with multiple legs, but chain allows finer length adjustments. With chain, you can add or remove a few links or use grab hooks to adjust length in the field. With wire rope, leg length is fixed at manufacture or requires special turnbuckles.
When it comes to hitch types, both slings can be used in vertical, choker, and basket hitches. Wire rope naturally crimps in chokers, often gripping loads well. Chain chokers tighten as load increases and are also effective but bulkier. Basket hitches of either type will double or triple the effective WLL depending on leg angles.
3. Durability and Maintenance
Chain slings usually outlast wire rope in abrasive or impact-prone environments. A steel chain link will resist nicks and cuts from sharp edges better than individual steel wires. If a wire rope rubs against a rough surface, individual strands can fray or break, whereas a chain link may only show slight wear.
However, wire rope slings offer progressive failure. Wire rope is made of many small wires. When overloaded or damaged, it typically doesn't snap instantly. Instead, individual wires break first. This provides a visual cue that the sling is compromised. As a result, it is easy for the operator to notice before it breaks completely, making it somewhat safer. By contrast, a chain can fail suddenly at one link if overstressed, which is why regular inspections are vital.
Both sling types require diligent maintenance to remain safe. As noted earlier, wire rope needs thorough lubrication to protect internal strands. Without lubrication, wire rope will suffer rapid wear, rust, and broken wires. It also needs to be kept from sharp bends or kinking. Chain needs its own upkeep: clean out grit, apply oil, and watch for stretched or bent links. A chain with a bent or cracked link is no longer safe; similarly, a wire rope with a severe kink must be replaced. Good maintenance extends service life: well-cared-for chain and wire slings can last for years.
4. Cost and Lifespan
In general, wire rope slings are more cost-effective initially. Steel wire is cheaper per foot than alloy chain, so a wire rope sling of a given capacity often costs less upfront. Wire rope is also lighter, reducing handling and shipping costs. However, chain slings, while pricier at purchase, often have a very long lifespan if not abused. A single rugged chain can survive many lifts over years. Chain links can sometimes be replaced, and fittings can be swapped, extending service life.
Wire rope slings typically wear out at cut points or fatigue, requiring replacement of the cable. Their protective galvanized or plastic coating can scratch off, exposing steel to rust. However, wire ropes are generally cheaper to replace than an equivalent chain sling if seriously damaged. The decision on cost-effectiveness depends on volume of use: for very frequent heavy lifts, a durable chain may be cheaper in the long run despite higher initial cost. For less frequent or medium-duty use, economical wire rope slings may suffice.
5. Environmental Suitability and Safety
Temperature is a key factor. Alloy chain handles high heat better. Steel maintains strength at red-hot temperatures; thus chain slings are common in foundries and steel plants. Wire rope can also handle elevated temperatures but usually has lower limits (depending on core material and lubrication). Neither metal sling is suitable for continuous use above ~400 °F without special design. In very cold conditions, both chain and wire become stiffer, but properly rated slings can operate in subzero weather.
Corrosive environments: Both metal types will corrode if untreated, so galvanizing or stainless steel is used if needed. Chain's relatively thicker metal may resist pitting slightly better, but any corrosion can weaken a link significantly. High-humidity or offshore jobs require extra attention: clean and dry slings after exposure.
Safety inspections: Both sling types are covered by standards. Before use, a competent person must inspect slings. For wire rope, inspectors count broken wires; a common rule is no more than 10 randomly broken wires per lay length. For chain, inspectors look for elongation, bent links, nicks, or wear beyond specified limits. Welding repairs or non-approved modifications must be avoided on both sling types. Every sling must have a legible tag with its WLL and grade.
A critical safety note: never exceed the rated WLL, and always account for hitch angle effects (slings at angles have reduced capacity). Maintain clear load paths and avoid side loading on hooks. Both chain and wire rope slings store potential energy; a sudden break can be dangerous. Proper care, training, and adherence to manufacturer guidance keep lifts safe.
