What is a sling in manufacturing?

Equipment that can be used to lift and lower loads

For the application in physical exercise known as “weightlifting equipment”, see exercise equipment

Lifting equipment, also known as lifting gear, is a general term for any equipment that can be used to lift and lower loads.[1] Types of lifting equipment include heavy machinery such as the patient lift, overhead cranes, forklifts, jacks, building cradles, and passenger lifts, and can also include smaller accessories such as chains, hooks, and rope.[1] Generally, this equipment is used to move material that cannot be moved with manual labor, and are tools used in most work environments, such as warehouses, and is a requirement for most construction projects, such as bridges and buildings. This equipment can also be used to equip a larger number of packages and goods, requiring less persons to move material. Lifting equipment includes any form of equipment that is used for vertical lifting, and equipment used to move material horizontally is not considered lifting equipment, nor is equipment designed to support.[2] As lifting equipment can be dangerous to use, it is a common subject of safety regulations in most countries, and heavy machinery usually requires certified workers to limit workplace injury.[3][4]

Safety Issues

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Failure or misuse of heavy machinery can lead to severe or fatal injury, leading regulations to be one of the largest debates in labor laws across the world. Each country sets its own regulations, and enforces different aspects of workplace safety when using lifting equipment.

In the United States

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The Occupational Safety and Health Administration sets regulations for all equipment.[3] Contractors are forced to uphold usually strict rules to ensure safety of workers. All machinery is required to be developed by a certified engineer, contractors must follow manufacturer procedures, all users be professionally trained before operating equipment, and equipment must be inspected regularly.

In the United Kingdom

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The Health and Safety Executive sets regulations on equipment in the United Kingdom, under the Lifting Operations and Lifting Equipment Regulations.[1] These regulations require equipment be registered on a Statutory Inspection Report Form, is adequate for the task, be subject to routine inspection, and the use of the equipment be properly planned out.

See also

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References

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Industrial lifting slings are at the heart of most overhead lifting operations. Used with lifting equipment such as forklifts or overhead cranes, they enable you to hoist, move, and position heavy loads safely and efficiently.

Lifting slings are broadly classified into three categories.

• Wire Rope Slings
• Chain Slings
• Synthetic Slings

Depending on their structure, material, and load limit, different lifting slings are suited to different operations. In this article, we’ll go over the basics of industrial lifting slings, discussing the advantages and disadvantages of each to help you make an informed decision. It will help you and select the most suitable sling for your project.

Wire Rope Slings

Wire rope slings, or cable slings, have always been the standard choice for heavy-duty operations, owing to their strength, abrasion resistance, resilience, and flexibility. To top that, they can also lift hot objects with ease.

Generally, these lifting slings are made of multiple wire strands twisted around a steel or fiber core. The material of the wire, coupled with the core and strand structure, determines the end-application of the sling.

Available in single-leg and multi-leg assemblies, cable slings are often paired with choker, vertical, and basket hitches. They are commonly used in the:

• Construction Industry
• Forging Facilities
• Automotive Industry
• Steel Mills
• Oil And Gas Industry
• General Manufacturing Industry

A) Advantages of Using Wire Rope Slings

Wire rope slings continue to be popular lifting solutions due to the following reasons.

• Wire ropes are less likely to break, thanks to their intricate woven structure. Additionally, the core in the center offers great reserve strength.
• They are lightweight, flexible, and can bend without distortion.
• They can endure abrasive wear and tear.
• Braided or multi-part cable slings are fairly resistant to kinking.
• Even if the wire rope on the sling bridles is damaged, the master links and hooks can be reused.

B) Disadvantages of Using Wire Rope Slings

That said, wire rope slings are not entirely without fault. Here are a few downsides to using these lifting devices.

• Cable slings usually have a low strength-to-weight ratio.
• The structure of the wire sling makes it difficult to inspect. This is dangerous since a single damaged link can jeopardize your lifting operation, putting the load and the crew in harm’s way.
• In case the wire sling’s initial lubrication wears off, you’ll have to apply the same type of lubricantas used by the sling manufacturers.
• Damaged cable slings cannot be repaired. The Occupational Safety and Health Administration(OSHA ) advises users to immediately discard slings with broken wires, severe locational bruising, evidence of heat damage, and missing identifications, among other things.
• It’s inadvisable to use or store steel core wire ropes at temperatures below -40°F or above 400°F.

Chain Slings

Often noted for their strength and durability, alloy chain slings are one of the toughest lifting solutions in the market. Besides being flexible, they can withstand high temperatures, collisions, and chemical exposure.

However, not all alloy chain slings are suitable for overhead lifting. According to data from Michigan State University, lifting and rigging jobs should only use grade 80 or grade 100 alloy chains for maximum safety and efficiency.

Being strong, tolerant to heat, and capable of lifting bulky loads regularly, alloy chain slings are widely used in environments with relatively harsh lifting conditions. These include foundries, steel mills, and heavy machine shops.

A) Advantages of Using Chain Slings

If you’re planning to use alloy chains for your next rigging project, here’s how these industrial lifting slings can benefit you.

• As mentioned, chain slings hold up in stressful operating climates. But be sure to check the sling’s specifications, proof-test it, and inspect for potential damage before putting it to action.
• Unlike wire ropes, chain slings can be repaired and re-certified. All you need to do is replace the chain links as required.
• Chain slings can function in temperatures between -40 °F to 400 °F without any significant reduction in their Working Load Limit.
• They are easy to adjust.

B) Disadvantages of Using Chain Slings

With regard to chain slings, the drawbacks are limited but significant. For starters, they are the most expensive of all lifting slings. Other disadvantages are as follows.

• Most chain slings are very heavy and difficult to manipulate. Plus, as the Working Load Limit increases, so does the weight of the chain.
• They can easily crush or bruise sensitive loads and finished parts.

Synthetic Slings

When it comes to lifting fragile and delicate loads, nothing measures up to the strength and flexibility of synthetic slings. These lightweight lifting solutions, usually crafted out of nylon or polyester, are available in an array of standardized sizes.

Synthetic slings are a go-to choice for hoisting polished, finished expensive and oddly-shaped items. While they are strong enough to lift heavy loads, their soft texture minimizes the risk of scratches and bruising. Furthermore, these industrial lifting devices are equally compatible with vertical, choker, and basket hitches.

As you would expect, synthetic slings play a big role in the construction industry due to their ease of operation and affordability. But they’re also used in sectors where finished products are moved from one point to another.

A) Advantages of Using Synthetic Slings

Given the many benefits of synthetic slings, it’s easy to see why they’re such a well-loved rigging and lifting choice.

• Synthetic slings are crafted from non-sparking and non-conductive fibers, making them a perfect choice for explosive environments.
• As mentioned, they have a wide range of applications across multiple industries.
• Their soft material protects expensive items from scratches and other lifting-related damage.
• Synthetic slings can easily adjust to the shape of misshapen loads and secure them firmly in place.
• They are fairly cost-effective.

B) Disadvantages of Using Synthetic Slings

That said, synthetic slings have several limitations, which often make them unsuitable for long-term applications.

• These lifting devices are unsuitable for high temperatures, owing to their relatively low heat resistance. However, some sling manufacturers do produce more temperature-tolerant variants of these slings.
• Synthetic slings are more prone to cuts and abrasions than wire ropes or chains. Also, they do not respond well to chemicals and UV rays. Each of these factors can significantly reduce its capacity to carry heavy loads.
• As a general rule of thumb, synthetic slings cannot be repaired. So, you’ll have to throw them out at the first signs of damage.

What to Consider When Selecting Industrial Lifting Slings?

It’s convenient to choose lifting slings once you have a detailed idea about how they work, what load types they are made for, and their optimal environment, among other things. You’ll need the right slings to drive your industrial lifting project at full steam. As a result, you must consider these factors.

• Weight and fragility of the load. If you already know how much the load weighs, you’ll have an easier time selecting a sling of suitable strength.
• The load’s center of gravity. Unless the object is properly centered, it may swing off-balance and crash into people or property nearby. For oddly-shaped objects, you can use synthetic slings to play it safe.
• Frequency of use. Generally, this determines the sling’s lifespan. Think about how often you’ll be using your lifting slings before you make your choice.

Other factors you should take into account are:

• Fitting requirements
• Height restrictions
• Attachment points
• Hitch type
• Sling angles
• Reach

Over to You

Given that rigging slings are an important aspect of your overhead lifting project, you’ll need to know them like the back of your hand. Hopefully, this guide will give you a fair notion about the different types of slings out there, along with their major pros and cons.

In case you have any additional queries regarding industrial lifting slings, or want to check out our inventory, feel free to reach out to Holloway Houston Inc. Our team of seasoned specialists will help you find exactly what you need for your next lifting job!