Deciding on Lifting with either Chains or Polyester Slings - The Pros and Cons

RSS

When it comes to lifting of loads, it is important the correct type of sling is used, both for its ease of use and for general safety compliance. Bearing in mind, these slings are used for the lifting and moving of a wide variety of applications, you have a choice of using steel chain assemblies or webbing sling assemblies. But, is it purely a personal choice or is it that different applications need specific sling types? So, let's see.

What factors should determine the choice of sling?

The material/item to be lifted - is it important that it should not be scuffed or damaged? if so, polyester should be the preferred choice as chains are much more likely to cause some damage?
The weight of the load. - is the sling certificated limit above the weight of the load?
The centre of gravity of the load.
The best slinging configuration that provides the proper balance for the load.
The working load limit of the sling.
The work rated load of the attachments and components of the sling.
The environmental conditions (temperature, humidity, presence of corrosive agents...)

What should you know when using any type of sling?

Be sure you know the correct use of the equipment, the slinging procedures and the sling strength factors to be applied before lifting. Always check the manufacturers' information before using.

All slings (new, altered, modified, or repaired) should be inspected by a competent person before they are used in the workplace, to make sure they are built to specifications, are not damaged, and will be appropriate for the work being performed.

So, based on these factors above, which is the type of sling that you should choose? Polyester webbing slings or chain slings.

Let us look at each in more detail.

Polyester Web Slings

Polyester web slings are a good choice where highly finished parts or delicate equipment must be protected from damage. The synthetic material has stretch and flexibility to help the slings mold to the shape of the load, gripping securely, while cushioning and absorbing shock more than a chain.

They are lightweight and very easy to handle.
They are non-sparking, non conductive and can be used safely in explosive atmospheres.
Polyester slings are typically not affected by grease, oil, moisture and certain chemicals. Check with the manufacturer to determine which conditions apply to the exact material you are using.
Polyester web slings are easily cut and have poor abrasion resistance when compared with chain and wire rope slings. Protect webbing from sharp corners, protrusions, or abrasive surfaces.
Protect slings from heat sources such as steam pipes, open flame and welding splatter.
Nylon slings are damaged by acids, but resist caustics.
Polyester slings are damaged by caustics but resist acids.
Wet frozen slings will have a reduced load capacity. Follow manufacturer's recommendations.
Sunlight, moisture, and temperatures above 82.2°C (180°F) damage both nylon and polyester slings.
Use slings made of the right material for the job.
Check the manufacturers' slings for their code number and the rated capacity. Reference charts showing slings and hitch rated capacities are available from manufacturers.
Inspect slings before using them.
Keep an inspection record for each sling.
Replace damaged slings, or repair only according to manufacturer's recommendations.

What should you do when selecting Polyester web slings?

Determine the weight of the load.
Refer to the manufacturer's reference chart for the capacity rating.
Check a sling before using it.
Prevent loading more than the rated capacity by considering sling angle.
Ensure that the sling choking action is on the webbing, not the hardware.

What should you avoid when using slings?

Do not drag slings across floors or other abrasive surfaces.
Do not drop slings with metal fittings.
Do not set loads down on top of slings.
Do not pull slings from under loads when the load is resting on the sling.
Do not weld anything hung from a sling.
Do not lengthen or shorten slings by tying knots.
Do not place stitch patterns (laps) on hooks, around sharp corners, or at choker bearing points.

What kind of damage makes a Polyester web-sling unusable?

Increased stiffness of sling material.
Acid or caustic burns.
Melted, burned or weld spatter damage.
Holes, tears, cuts, snags.
Broken or worn stitching.
Excessive abrasive wear.
Knots in any part of the sling.
Crushed webbing or embedded particles.
Bleached sling colour.
Defective fittings (twisted, corroded, cracked, etc.)
Exposure to extreme temperatures (lower than -40°C or higher than 90°C)

See Cardno Polyester Flat Slings https://cardno.co.uk/collections/flat-slings

Chain sling

Inspecting Chain sling before use

A competent person must also inspect chain slings periodically, and at least once a year. Inspection frequency is based on how often the sling is used, the types of lifts being performed, the conditions in which the sling is being used, and past experience with service life of similar slings and usage. If the sling is used in more severe conditions, then the inspection should be performed every 3 months. Inspections must be recorded.

In addition to the inspections by a competent person, the user should inspect chain slings and accessories before each use and before placing into storage. Check for visible faults in links and hooks and distortion of fittings.

Checking the Sling

Clean sling before inspection.

Check identification tag
Hang the chain up or stretch the chain out on a level floor in a well-lighted area. Remove all twists. Measure the sling length. Discard if a sling has been stretched.
Make a link-by-link inspection and discard if:

a) Wear exceeds 15% of a link diameter.

b) Cut, nicked, cracked, gouged, burned, weld splattered, or corrosion pitted.

c) Deformed, twisted or bent chain links or components.

d) Stretched. Links tend to close up and get longer.

Check master link, load pins and hooks for any of the above faults. Hooks should be removed from service if they have been opened more than 15% of the normal throat opening, measured at the narrowest point, or twisted more than 10° from the plane of the unbent hook.
Manufacturers' reference charts show sling and hitch capacities. Record manufacturer, type, load limit and inspection dates.

How should you use chain slings safely?

Always know how to properly use the equipment, slinging procedures before attempting the lift operation.
Inspect the slings and accessories before use for any defects.
Replace broken safety latches.
Find out load weight before lifting. Do not exceed rated load of the sling.
Check whether chain slings fit freely. Do not force, hammer or wedge chain slings or fittings into position.
Keep hands and fingers from between load and chain when tensioning slings and when landing loads.
Ensure the load is free to be lifted.
Make a trial lift and trial lower to ensure the load is balanced, stable and secure.
Balance the load to avoid over-stress on one sling arm or the load slipping free.
Lower the working load limit if severe impact may occur.
Pad sharp corners to prevent bending links and to protect the load.
Position hooks of multi-leg slings facing outward from the load.
Cordon off the area.
Reduce the load limit when using chain in temperatures above 425°C (800°F).
Store chain sling arms on racks in assigned areas and not lying on the ground. The storage area should be dry, clean and free of any contaminants which may harm the sling.

What should you avoid when using chain slings?

Avoid impact loading: do not jerk the load when lifting or lowering the sling. This motion increases the actual stress on the sling.
Do not leave suspended loads unattended.
Do not drag chains over floors or attempt to drag a trapped sling from under a load. Do not use a sling to drag a load.
Do not use worn-out or damaged slings.
Do not lift on the point of the hook.
Do not overload or shock load a sling.
Do not trap slings when landing the load.
Do not splice a chain by inserting a bolt between two links.
Do not shorten a chain with knots or by twisting other than by means of an integral chain clutch.
Do not force or hammer hooks into place.
Do not use homemade connections. Use only attachments designed for the chain.
Do not heat treat or weld chain links: the lifting capacity will be reduced drastically.
Do not expose chain links to chemicals without the manufacturer's approval.
Do not stand in line with or next to the leg(s) of the sling that is under tension.
Do not stand or pass under a suspended load.
Do not ride on sling.

See Cardno Chain Sling Assemblies here https://cardno.co.uk/collections/chain-assemblies

To Summarise

Polyester Webbing sling

For most general lifting applications, web slings are more than adequate as they are both lightweight and flexible.

Web slings are normally made from either nylon or polyester material. While nylon has better shock absorption, polyester provides better load control. Where they differentiate, though, is in their suitability in certain applications. Nylon slings are mostly used in applications with oil, alkaline, and grease, but are not suitable for acids and bleaches, whereas, polyester slings can be used with common acids and bleaches, but not with concentrated acids.

Lifting Sling Simplex with 6 tonne working load limit

Advantages of web sling:

Lightweight, economical, flexible, easy to use, water and rustproof.

Disadvantages of web sling:

Unsuitable for heavy loads and high temperatures, breakdown due to exposure to UV radiation, shorter product life.

Chain sling

Regarding chain slings, they are the most suited for industrial applications and heavy load lifting. for these reasons, chain slings are extensively used in steel production plants and environments operating at high temperatures (up to 400-degree Fahrenheit). Chain slings are designed for continuous use, due to their durable strength and long life. They are also more suited to be used in facilities with harsh conditions like foundries and heavy machine factories.

Lifting Chain Brother 4 legs with sling hooks

Advantages of the chain sling:

Chain slings are resistant to corrosion, chemicals, and UV exposure and they are also not affected by dirt, oil or grease. The longer the chain, the higher the working load limit, the heavier the sling will be.

Although more expensive to purchase, chain slings can be repaired if damaged and individual chain links or link segments can be replaced, so, could work out cheaper in the long run!

Disadvantages of chain sling:

Heavy, higher purchase cost, more difficult to handle and more likely to damage or scuff the item to be lifted.

We hope that this blog has proved useful to you in deciding on the type of sling you will need for your operations! At the end of the day, though, it is YOUR choice. BUT, if you are still not sure, then give us a call, (see link for contact details) we would be delighted to help you. Contact us

← Previous Post