A wire rope sling's capacity depends on four things: the rope diameter, how the sling is made, the hitch, and the sling angle. The charts below give rated capacities for standard 6x19 and 6x36 class EIPS IWRC slings with mechanical (pressed) splices, the most common wire rope sling in use. Below the charts: how working load limits are set, how to read a sling chart, and how to size a sling for your lift.
Quick answer: a 1/2" EIPS IWRC wire rope sling is rated about 2.5 tons vertical, 1.9 tons in a choker and 5 tons in a basket with vertical legs. A 2-leg bridle of the same rope is good for about 4.3 tons at 60°, 3.5 tons at 45° and only 2.5 tons at 30°. Always rig to the tag on the sling in your hand.
Wire rope sling capacity chart: single-leg hitches
Rated capacity in tons (2,000 lb) for 6x19 and 6x36 class EIPS IWRC slings with mechanical splices, 5:1 design factor. Choker values assume a choke angle of 120° or more. Basket values assume vertical legs and a large enough bend.
| Diameter (in) | Vertical | Choker | Basket (vertical legs) |
|---|---|---|---|
| 1/4 | 0.65 | 0.49 | 1.3 |
| 5/16 | 1 | 0.75 | 2 |
| 3/8 | 1.4 | 1 | 2.8 |
| 7/16 | 1.9 | 1.4 | 3.8 |
| 1/2 | 2.5 | 1.9 | 5 |
| 9/16 | 3.2 | 2.4 | 6.4 |
| 5/8 | 3.9 | 2.9 | 7.8 |
| 3/4 | 5.6 | 4.2 | 11 |
| 7/8 | 7.6 | 5.7 | 15 |
| 1 | 9.8 | 7.4 | 20 |
| 1-1/8 | 12 | 9 | 24 |
| 1-1/4 | 15 | 11 | 30 |
| 1-3/8 | 18 | 14 | 36 |
| 1-1/2 | 21 | 16 | 42 |
Multi-leg bridle sling capacity chart
Rated capacity in tons for 2-leg, 3-leg and 4-leg bridle slings, by the angle of the legs from horizontal. Same rope and splice as above. A 4-leg bridle is rated the same as a 3-leg, because on a real load you can't count on all four legs sharing the weight.
| Diameter (in) | 2-leg 60° | 2-leg 45° | 2-leg 30° | 3/4-leg 60° | 3/4-leg 45° | 3/4-leg 30° |
|---|---|---|---|---|---|---|
| 1/4 | 1.1 | 0.92 | 0.65 | 1.7 | 1.4 | 0.97 |
| 5/16 | 1.7 | 1.4 | 1 | 2.6 | 2.1 | 1.5 |
| 3/8 | 2.4 | 2 | 1.4 | 3.6 | 3 | 2.1 |
| 7/16 | 3.3 | 2.7 | 1.9 | 4.9 | 4 | 2.8 |
| 1/2 | 4.3 | 3.5 | 2.5 | 6.5 | 5.3 | 3.7 |
| 9/16 | 5.5 | 4.5 | 3.2 | 8.3 | 6.8 | 4.8 |
| 5/8 | 6.8 | 5.5 | 3.9 | 10 | 8.3 | 5.8 |
| 3/4 | 9.7 | 7.9 | 5.6 | 15 | 12 | 8.4 |
| 7/8 | 13 | 11 | 7.6 | 20 | 16 | 11 |
| 1 | 17 | 14 | 9.8 | 25 | 21 | 15 |
| 1-1/8 | 21 | 17 | 12 | 31 | 25 | 18 |
| 1-1/4 | 26 | 21 | 15 | 39 | 32 | 22 |
| 1-3/8 | 31 | 25 | 18 | 47 | 38 | 27 |
| 1-1/2 | 36 | 30 | 21 | 55 | 45 | 31 |
Values are calculated from the vertical rating and the leg angle, rounded down slightly. Hand-tucked splices, fiber cores and other grades rate differently. The tag on the sling is the final word; if the tag is missing or unreadable, the sling comes out of service.
What is the working load limit of a wire rope sling?
The working load limit (WLL), also called rated capacity, is the most a sling may lift in a given hitch under normal conditions. It's the sling's minimum breaking strength divided by a design factor, which is 5:1 for wire rope slings under ASME B30.9.
Example: a sling with a 20,000 lb breaking strength and a 5:1 design factor has a WLL of 20,000 ÷ 5 = 4,000 lb. The extra margin covers shock loading, wear, bending around the load and small errors in estimating weight. It is not spare capacity to use.
The rope's breaking strength depends on its construction and core. Our guide to 6x19 vs 6x37 wire rope and IWRC vs fiber core has the breaking strength chart by diameter.
How to read a wire rope sling chart
- Find the diameter down the left column.
- Pick the hitch. Vertical is the baseline. A choker reduces capacity to about 75% because the rope is bent hard at the choke point. A basket doubles it, because two legs share the load, but only when the legs are vertical and the load doesn't bend the rope too sharply.
- For bridles, use the leg angle. Measure the angle between each leg and the horizontal. The flatter the legs, the less the sling can lift.
- Compare to the load, with the weight known, not guessed. If the load is close to the limit, go up a size.
Why sling angle matters so much
When sling legs spread out, each leg pulls sideways as well as up, so it carries more than its share of the weight. The load on each leg grows as the angle flattens:
| Leg angle from horizontal | Load on each leg (2-leg lift of 1,000 lb) | Capacity vs. vertical legs |
|---|---|---|
| 90° (vertical) | 500 lb | 100% |
| 60° | 577 lb | 87% |
| 45° | 707 lb | 71% |
| 30° | 1,000 lb | 50% |
At 30° each leg carries the full weight of the load. Avoid leg angles under 30°. Our guide to how lifting angles affect sling capacity covers the math in detail.
Other things that lower a sling's capacity
- Sharp edges and tight bends: bending wire rope around a small diameter cuts its strength. Use sleeves or edge protection and avoid bending the body of the sling around anything smaller than the rope allows.
- Choke angle: chokes tighter than 120° reduce capacity further.
- Heat: IWRC slings can handle more heat than fiber core, but very hot loads reduce capacity. Ask before lifting anything hot.
- Wear and damage: broken wires, kinks, crushing, corrosion or heat damage mean the sling comes out of service. See common wire rope sling failures.
- The hardware: the shackle, hook or master link has to be rated at least as high as the sling. Our shackle guide has shackle WLLs by size.
How to size a wire rope sling for your lift
- Know the load's weight and where its center of gravity is.
- Choose the hitch and, for bridles, the leg angle you can achieve with the headroom you have.
- Find the smallest diameter on the chart whose capacity beats the load in that hitch and angle.
- Check the shackles, hooks and lifting points match or beat that capacity.
- Inspect the sling before the lift and confirm the tag matches.
Custom wire rope slings from Elko
We build single-leg, 2-leg, 3-leg and 4-leg wire rope slings to length, tagged with their rated capacity, at our Salt Lake City, Elko, Phoenix and Safford branches. Lifting with synthetic slings instead? Check the round sling capacity chart and color code.
Wire Rope Sling Capacity FAQs
How much can a 1/2-inch wire rope sling lift?
A 1/2" EIPS IWRC sling with mechanical splices is rated about 2.5 tons vertical, 1.9 tons in a choker and 5 tons in a basket with vertical legs. Check the tag on your sling.
What design factor is used for wire rope slings?
5:1 under ASME B30.9. The rated capacity is one-fifth of the sling's minimum breaking strength.
Does a basket hitch double the capacity?
Only when both legs are vertical. As the legs spread, the basket capacity drops the same way a bridle's does.
Why is a choker hitch rated lower?
The rope bends sharply where it chokes around itself, which concentrates stress. A choker is rated at about 75% of vertical, and less if the choke angle is under 120°.
Is a 4-leg sling stronger than a 3-leg sling?
It's rated the same. On a rigid load only three legs reliably share the weight, so a 4-leg bridle is rated as if it had three.
What's the minimum safe sling angle?
Keep legs at 30° or more from horizontal. Below that, the load on each leg climbs very quickly.
