How to Choose a Lifting Sling
Choosing a lifting sling can be overwhelming at first - there are a lot of options to choose from! To help you narrow down your selection, we've broken down three of the most important considerations: material, style, and rating.
If you are still unsure about which lifting sling is best for your application after looking through this page, contact our knowledgeable sales staff - they will be glad to answer any questions you may have, help you place an order, or discuss our custom sling capabilities.
Choose by Material
Nylon Slings
- Most widely used multi-purpose sling
- Flexibility of the fabric prevents it from locking up on a load
- Strong, easy to handle, and relatively inexpensive
- Unaffected by oil and grease
- Resilient to aldehydes, ethers, and strong alkalies
- Not suitable for use with acids or bleaching agents
- Stretches approximately 8-10% at rated capacity
- Should not be used in temperatures over 194°F (90°C)
Polyester Slings
- Flexibility of the fabric prevents it from locking up on a load
- Unaffected by common acids and hot bleaching agents
- Not suitable for use around concentrated sulfuric acids or alkaline
- Stretch approximately 3-5% at rated capacity
- Should not be used in temperatures over 194°F (90°C)
- Lightweight polyester material is easy to handle and store when not in use
Wire Rope Slings
- Offers high strength and flexibility in a smaller diameter
- 6x19 class is most widely used due to a good combination of flexibility and wear resistance
- 6x37 class is used primarily in larger diameter wire rope; large number of strands per wire make it more flexible but lessens resistance to abrasion
- 7x7x7 class utilize ultra-flexible and corrosion-resistant galvanized aircraft cables
Chain Slings
- Strong, durable, flexible; collapses for easy storage
- Available in Grade 100 and 120 lifting chain
- Often used in high temperature or under adverse conditions that would normally destroy or wear other types of slings
- Wide variety of hook end fittings available
- Price can be substantially higher than the other types
- Generally do not stretch at rated capacity (or very minimally), but can stretch 15-20% prior to failure
High Performance Roundslings
- Made from high performance inner fibers with a protective outer jacket
- Lightweight and stronger than comparable strength wire rope and polyester slings
- UV- and abrasion-resistant
- Load-conforming
- Available with a variety of core yarns, including Ultra High Modulus Polyethylene and K-Spec®
Choose by Style
Click below to learn about and compare different styles of slings:
Eye & Eye Slings
Eye & Eye Slings
Choose by Rating
Another factor to consider when choosing the right sling for you is the working load limit - you'll need to choose a sling that is strong enough to handle whatever you are lifting. This sounds fairly simple - the lifting capacity of the sling must be greater than the weight of your load - but there are a couple of additional variables that can affect what lifting capacity you'll need, such as hitch type, D/d ratio and angled lifting multipliers.
Depending on the sling type, the sling will be tagged with rated capacities for the different application hitches / working load limits at degrees of lift.
Hitch Type
There are three standard hitches slings are used in - choker, vertical, and basket. The hitch you choose can affect your load capacity, and some slings are only suited for one or two of the hitches.
Basket Hitch
A basket hitch cradles the load, with both ends of the sling attached overhead.
Vertical Hitch
When you use a vertical hitch, one end of the sling is connected to the load, while the other is attached overhead. A vertical hitch load capacity is 50% of the basket capacity.
Choker Hitch
With a choker hitch, one end of the sling is passed through the other, then connected overhead, circling the load. Depending on the type of sling, a choker hitch load capacity can be up to 80% of the vertical capacity. Check your individual sling to confirm it's ranking before use.
D/d Ratio
Many slings have a recommended D/d ratio - the ratio of the diameter (D) around which the sling is bent, divided by the diameter (d) of the sling body.
Example: A 3/4" diameter (d) wire rope is used to lift a 12" diameter (D) pipe. 12 divided by 3/4 gives you a ratio of 16:1.
Why is this important? When a sling is bent too much, there can be a significant loss of strength. If you exceed the recommended D/d ratio, the lifting capacity is reduced, and there is an increased chance of sling fatigue, deterioration, and wear.
Learn more about D/d ratios on our blog.
D/d Ratio photo courtesy of Unirope
Lifting at Angles
For lifting applications where you are not lifting at a 90 degree angle, the working load limit of the sling is reduced. To ensure your sling is still properly rated to lift your load, you will need to do some calculations.
To calculate the capacity, follow these steps:
- Divide total load weight by the number of legs supporting the load. This will give you the maximum load weight per sling leg. Keep in mind this is assuming a balanced load over the center of gravity with equal weight distributed on each leg.
Example: Your load weighs 3,000 lbs. and you have a sling with 2 load-bearing legs. 3,000 / 2 equals a maximum load weight of 1,500 lbs. on each leg. - Using the below chart, choose the applicable load factor multiplier.
Example: Your lift angle is 75 degrees, giving you a multiplier of 1.035. - Multiply the load factor multiplier with the maximum load on each sling leg. Then take that number and multiply it by the number of weight-bearing legs. This will give you the capacity needed to safely lift your load.
Example:1,500 x 1.035 is 1,533. Then multiple 1,553 by your 2 legs, which is 3,106. Your sling's capacity will need to be at least this number to safely lift your load.
| Leg Angle | Load Factor Multiplier |
| 90° | 1.000 |
| 85° | 1.003 |
| 80° | 1.015 |
| 75° | 1.035 |
| 70° | 1.064 |
| 65° | 1.103 |
| 60° | 1.154 |
| 55° | 1.220 |
| 50° | 1.305 |
| 45° | 1.414 |
