The Science
of Magnet Lifting: How Do Magnets Work to Lift Heavy Objects?
Magnets are an exciting concept, but it is amazing how large magnets specifically made for lifting heavy items around construction sites work when applied to an industrial setting
In this article, we’ll look at the most commonly sought-after types of magnet lifters, their mechanisms and how they each perform. Once you determine which would be best suited for your lifting job, call Keble’s Trading to discuss your requirements and allow us to assist you with your lifting needs.
Types of Magnet Lifters
When referring to magnetic properties, magnet lifters can be categorised into three (3) types: permanent magnet lifter, electromagnet lifter and permanent electromagnet lifter. Let’s have a look at each of these types.
Permanent magnet lifter
these magnets are primarily utilised for lifting press moulds, blocks, steel plates, etc. As well as this, they are also used to assist with loading and unloading machinery during operation. Further, they can elevate moving iron blocks and other industrial magnetic materials. Permanent magnet lifters are simple to use and operate, as they are safe to handle therefore being widely used as lifting devices in docks, factories, transportation and warehouse industries. By incorporating these types of heavy-duty magnets into your operations, you can drastically improve your productivity.
Electromagnet lifter
these types of industrial-strength magnets are also known as electromagnetic lifters or lifting electromagnets as they are known for delivering a significant holding power through an inbuilt specialised, penetrating magnetic force which is capable of lifting thicker items such as bundled rebars, beam blank profiles, multiple sheets, and scrap items.
Permanent electromagnet lifter
These heavy-duty magnets have a permanent magnetic field, but when provided with power, the magnetic field is offset. This electromagnet type is utilised when the magnetic force is necessary to run This type of magnet lifter is highly energy-saving and safer for the handler than the electromagnet lifter, as the former expends no power during the lifting process. Electricity is only utilised in the MAG and DEMAG stages. Further safety benefits include during a sudden power failure, the load being lifted will not fall or detach as the magnetic force remains on.
Safety Considerations for Working with Magnet Lifters
Safety considerations when using magnetic lifters can include:
- Magnets flying together or toward steel, objects can attribute severe pinching or abrasions to the skin.
- Magnets can splinter and break upon impact, which can cause an eye injury. Goggles are highly advised to be worn when handling.
- Children must never be allowed to handle or play with these heavy-duty magnets.
- Avoid applying fire or attempting to oven-heat a magnet lifter, and be mindful to avoid grinding or cutting these types of magnets. Procedures such as these impose a
risk of both oxygen absorption and possible shattering. As well as this, enclosed magnets, if heated, may explode.
Difference Between Magnetic Lifting and Mechanical Lifting
The most significant difference between magnetic lifters and mechanical lifting devices is that magnetic lifters are inbuilt with magnetic force, while the other uses manual force. Manual force includes lifting devices such as forklifts, overhead cranes and mechanical jacks.
Magnetic force can attach itself to steel items, and mechanical lifting devices can lift objects constructed of various materials for items with a magnetic pull.
How to Choose the Right Magnet Lifter for Your Lifting Needs
Do you know how to determine the type of magnet lifter for your lifting needs? If not, let’s look at what should be considered before investing in one:
Step #1 – Consider the lift rating when choosing a lifting magnet and the weight of the materials needing to be lifted. Concerning lift ratings refers to the maximum amount of weight that a lifting magnet can lift, and exceeding this can be a potential safety hazard. Smaller types of lifting magnets have a lift rating of 90 - 180 kilograms, whereas some larger ones have a lift rating of up to around 6000kg It is highly advisable to consider the loadbearing weight of the materials, so you know which lifting magnet will support the load.
Step #2 – With most lifting magnets offering some control mechanism for the handler, it’s important to note that lifting magnets don’t produce a magnetic field all of the time. Instead, they provide a control application that allows the handler to turn off and on the magnetic field. When selecting a lifting magnet, you should consider its control application. Many lifting magnets have a simple lever-based control mechanism. You can manoeuvre the lever to operate the magnetic field.
Step #3 – Another aspect to consider when selecting a lifting magnet is the operating temperature–the temperature at which the lifting magnet will operate. An operating temperature of less than 80 degrees indicates that the lifting magnet will operate at less than 80 degrees.
Step #4 – Consider the type of material that the lifting magnet is made of - while all lifting magnets contain a high-powered magnet they are also constructed of other heavy-duty materials. Lifting magnets built of stainless steel feature a stainless steel body that plays host to a powerful magnet. Stainless steel lifting magnets are resilient, tough and longlasting. And with this iron alloy, they are naturally protected from rust and corrosion. These are just a few things to consider when selecting a lifting magnet.
FAQs:
Which magnet is used for lifting heavy loads?
The three most popular choices for lifting heavy loads are permanent magnet lifters, electromagnet lifters, and permanent electromagnet lifters.
Does magnet size affect lifting strength?
Smaller types of lifting magnets have a lift rating of 90 - 180 kilograms, whereas some larger ones have a lift rating of up to around 6000kg. It is highly advisable to consider the loadbearing weight of the materials, so you know which lifting magnet will support the load.
How can you tell if a magnet is strong or weak?
The maximum energy product of a magnet is measured in Mega Gauss Oersteds (MGOe). This is the primary indicator of a magnets’ strength’. In general, the higher the maximum energy product value, the greater the magnetic field the magnet will generate in a particular application.