Webbing Sling Q&A: Heavy-Duty Strength for Delicate Lifts

webbing sling from hercules slr

WEBBING SLING: EVERYTHING YOU NEED TO KNOW

If you’re a rigger or work in material handling, you likely encounter webbing slings often in your work. A synthetic webbing sling is fantastic to lift delicate or soft materials, since their soft surface offers more protection than abrasive materials, like wire rope. 

Webbing slings come in two types — duplex and simplex. A duplex webbing sling is made with two synthetic fabric layers stitched together for extra reinforcement. A simplex webbing sling is made with only one synthetic fabric layer.

“Just one layer? That won’t do anything,” you might be thinking—but how wrong you’d be! Even though a webbing sling may not have the same reputation for strength as say, steel, a webbing sling is surprisingly strong. 

There are some misconceptions and often-asked questions about synthetic materials in the industry—so we’ve asked Hercules SLR experts from our Brampton, Ontario branch to help. 

Read on to find out the questions we hear about webbing slings, and how our experts’ answer. 

Q: What are they usually made from? 

Answer: A flat webbing sling is usually made from woven polyester, nylon (otherwise known as polyamide) and polypropylene.   

Q: Do flat webbing slings come in just one width? 

Answer Flat webbing slings come in different widths – but their ultimate flexibility and strength is noted by the number of webbing layers stitched together. 

webbing sling at hercules slr

Q: Should I use paint or dye to colour code webbing slings? This should help me identify them quickly and easily, right?

AnswerNO! Don’t use paint to colour code webbing slings—the solvents in the paint could corrode the synthetic material. A torn or broken sling is unsafe, and will drastically reduce it’s SWL. To identify a synthetic sling’s material, look for the label colour: 

Polyester (PES)—Blue Label, or blue with a green line down the center of the webbing. 

Polyamide (PA)—Green label

Polypropylene (PP)—Brown label

Q: What chemicals will affect webbing slings?

Answer: Polyester isn’t affected much by acid, but alkali’s will damage a polyester webbing sling. An alkali, or alkaline is basically a substance with a pH level higher than 7. Examples of alkali substances are sea water, baking soda, bleaches, lye and even blood. Polyamide’s are basically immune to alkali damage, but are damaged by even moderately-strength acids. They can also lose up to 15% of their SWL when wet. Polypropylene is resistant to acids and alkali’s, which makes them a good choice when you have to lift something which needs protection from chemicals. Be sure the polypropylene is stabilized to protect from ultraviolet degrading. 

Q: What markings should I look for on a webbing sling?

Answer: Look for the safe-working load (SWL), identification number and the label’s colour code.

 Q: How do I store my webbing sling?

AnswerIt definitely matters! Be sure to store your slings in a dry, cool place. Keep them out of sunlight or other ultra-violet radiation, and don’t store them in damp conditions. 

Q: So, they’re really strong – does that mean I can use them to lift anything? 

AnswerDon’t use a webbing sling for a critical lift! Make sure you use extra caution and have a detailed lifting plan for using a webbing sling with delicate or fragile lifting operations. 

Q: Okay, so what’s a critical lift?!

Answer: A critical lift is defined by WorkSafe BC as a lift with high risk factors that could cause the crane or hoist to fail, or poses a significant potential harm to human life. A critical lift is also one that needs a detailed rigging plan before the operation. 

Other factors that can make a lift critical are: 

  • When a piece of powered lifting equipment exceeds it’s rated capacity by 75%;
  • A mobile crane or boom truck goes over rated capacity by 90% lifting a load over 50% of its maximum permitted load radius; 
  • Tandem lifts— which is when more than one piece of powered lifting equipment is used, or is used to lift another piece of lifting equipment);
  • A person is being lifted;
  • The load is under-water or submerged. 

Q: Can I tie a knot in a webbing sling to make it shorter?

Answer: Never! Don’t knot, tie or twist a webbing sling. Don’t manipulate the sling’s angle, either—use the sling however the angle forms naturally.  

hercules slr webbing sling formation types
Figure 1—Webbing Sling Types

Q: When should I not use a webbing sling? 

Answer: Don’t use a webbing sling if you don’t know the SWL. Don’t use if the eyes or other part of the webbing sling is damaged, if the sling’s eye opens more than 20°. There are 5 different types of possible webbing sling eye formations—see figure 1. If using a Type 1 webbing sling (called a choker sling), be sure to protect the eye before use. 

Q: What should I keep in mind when using a webbing sling? 

Answer: There are a few things to consider to use a webbing sling safely—you should always: 

  • Avoid shock-loading;
  • Protect the sling with sleeves when sharp edges could tear its fabric—friction can cause heat damage, which is the most common form of ‘heat’ damage to webbing slings. To prevent, don’t let the sling run along the load’s surface and that it’s not pulled on any sharp corners. This is also known as ‘point loading’, when the load is pulled on a sharp corner, creating heat which results in heat fusion in the sling material. 
  • Never pull a sling from underneath a load.

DOWNLOAD OUR SYNTHETIC SLING INSPECTION GUIDE

References: https://en.oxforddictionaries.com/definition/alkali, https://www.worksafebc.com/en/law-policy/occupational-health-safety/searchable-ohs-regulation/ohs-regulation/part-14-cranes-and-hoists 

Hercules SLR is part of the Hercules Group of Companies which offers a unique portfolio of businesses nationally with locations from coast to coast. Our companies provide an extensive coverage of products and services that support the success of a wide range of business sectors across Canada including the energy, oil & gas, manufacturing, construction, aerospace, infrastructure, utilities, oil and gas, mining and marine industries.

Hercules Group of Companies is comprised of: Hercules SLRHercules Machining & Millwright ServicesSpartan Industrial MarineStellar Industrial Sales and Wire Rope Atlantic.

We have the ability to provide any solution your business or project will need. Call us today for more information. 1-877-461-4876. Don’t forget to follow us on FacebookTwitter and LinkedIn for more news and upcoming events.

Poly-What?! All About Synthetic Slings

what-are-synthetic-slings

Synthetic slings are generally available in two varieties – flat-woven web slings and round slings. Textile slings should perform in accordance with ASME standards B30.9-5.

Synthetic Slings: flat-woven web sling (or webbing sling)

Synthetic flat-woven web slings are usually made with woven polyester, polyamide (which is a fancy word for nylon) or polypropylene, and have an eye (basically, a loop) stitched at each end. They are available in Simplex (one layer) or Duplex (two layers).

Web slings are made with a safety factor of at least 5:1 – although other industries may require a higher safety factor.

Synthetic Slings: round slings

Round slings (also known as ’roundslings’) are made from load-bearing fibres with a protective, abrasion-resistant outer later. Their round form is known as ‘endless construction’, and are available in different lengths and capacities.

Synthetic Slings: beat the heat

Consider the temperature of both your surroundings and the load you will lift – synthetic materials have selective resistance to heat, which will effect which sling you choose.

Synthetic sling heat ranges are:

  • Polyester and polyamide: -40°C to 100°C
  • Polypropylene: -40°C to 80°C

These synthetic materials protect against a variety of chemicals, however – they offer different levels of protection against chemicals like acids. Synthetic sling chemical resistance is:

  • Polyamide (Nylon): Resistant to the effects of alkalis, but is attacked by acids.
  • Polyester: Resistant to acids, but damaged by alkalis.
  • Polypropylene: Shows little affect from acids or alkalis. Sustains damage from solvents and paint.
Synthetic Slings: colour codes

Synthetic material in slings are colour coded, in order to identify them properly. The label will be a specific colour, and may also have the type of material written as an abbreviation.

The colour codes are:

what-are-synthetic-slings-
Figure 1: Synthetic Sling Labels

 

Synthetic Slings: eye formations
what-are-synthetic-slings
Figure 2: web sling types

The loop at the end of the web sling is called an eye formation – there are various formations to suit different applications.

There are six different types of web sling types – see figure 2. The six names for these slings are:

  • Type 1—Choker
  • Type 2—Basket
  • Type 3—Eye & Eye
  • Type 4—Twisted Eye
  • Type 5—Endless
  • Type 6—Reversed Eye
Synthetic Sling: round slings

These are made with multiple, high-tenacity yarns, which are covered with a protective sleeve. These are usually made from polyester – but, polyamide (nylon) and polypropylene are available too.

To identify these slings, an identification label is sewn into the cover which details user information and traceability requirements.

They are flexible, light-weight and very flexible.

Synthetic Sling: pre-use inspection

Follow these steps before using your synthetic sling each time – this will ensure you and coworkers will stay safe, and eliminates potential of the sling breaking and damaging the load.

If you find damage on your synthetic sling, it should be removed from service immediately – refer it to a competent person to have it inspected and repaired if necessary.

During your pre-use check, you should:

  • Check the sling label is present and legible and includes manufacturer, rated load for at least one hitch, material type, number of legs (if more than one) and the manufacturers code/stock number.
  • Check that the sling body has no signs of tears, cuts or severe abrasion
  • Check formed eyes for damaged stitching
  • Verify end fittings (where present) function correctly and are undamaged.
  • Check for signs of chemical damage.
  • Check that sling has undergone its periodic thorough inspection.
  • No knots in sling.
Synthetic Slings: shackles, hooks n’ hardware

When you attach a sling to hooks or shackles, take care to ensure the slings don’t bunch around the accessory. Bunching can cause damage since only a portion of the webbing supports the load.

When securing a load with webbing slings, don’t be concerned with the d/d ratio (diameter around the bent sling divided by the body diameter of the sling) – but you must consider the width of the webbing. Follow the manufacturer’s recommendations when you lift with synthetic web slings.

what-are-synthetic-slings
Note: the sling that lies in the shackle fits perfectly – there’s no bunching or a sling that protrudes from the shackle pin.

Hercules SLR – Custom Rigging and Lifting Solutions

Hercules SLR offers custom lifting solutions. We’ll match you with the best equipment and hardware for your project needs, and we’ll customize equipment to meet your specifications.

Need a lift? Drop us a line at info@herculesslr.com to speak with one of our rigging experts – we’ll take you where you need to be.

Need proof? Read about the Frankensling we made for The Town of Oakville Marina, our rigging fundamentals course that Hercules staff from across Canada completed at the Hercules Training Academykeep your synthetic round slings in good working order with our Free Downloadable Synthetic Round Sling Inspection Guide or read our blog on how to prevent synthetic round sling damage.


Hercules SLR is part of the Hercules Group of Companies which offers a unique portfolio of businesses nationally with locations from coast to coast. Our companies provide an extensive coverage of products and services that support the success of a wide range of business sectors across Canada including the energy, oil & gas, manufacturing, construction, aerospace, infrastructure, utilities, oil and gas, mining and marine industries.

Hercules Group of Companies is comprised of: Hercules SLRHercules Machining & Millwright ServicesSpartan Industrial MarineStellar Industrial Sales and Wire Rope Atlantic.

We have the ability to provide any solution your business or project will need. Call us today for more information. 1-877-461-4876. Don’t forget to follow us on Twitter, LinkedIn and Facebook for more news and upcoming events.