What Are Some Uses Of Permanent Magnets

Neodymium Magnets 03/01/2020

Types of Magnets

Magnets are objects that generate a magnetic field, a force-field that either pulls or repels certain materials, such as nickel and iron, but what are magnets made of and what are the different types of magnets? We give you everything you need to know about the types of magnets and their strengths and uses.

What Are the Different Types of Magnets?

Of course, not all magnets are composed of the same elements, and thus can be broken down into categories based on their composition and source of magnetism.

Permanent magnets are magnets that retain their magnetism once magnetized.

Temporary magnets are materials magnets that perform like permanent magnets when in the presence of a magnetic field, but lose magnetism when not in a magnetic field.

Electromagnets are wound coils of wire that function as magnets when an electrical current is passed through.

By adjusting the strength and direction of the current, the strength of the magnet is also altered.

Below we breakdown the various types of magnet available.

Permanent Magnets

There are typically four categories of permanent magnets: neodymium iron boron (NdFeB), samarium cobalt (SmCo), alnico, and ceramic or ferrite magnets.

Neodymium Iron Boron (NdFeB)

This type of magnet is composed of rare earth magnetic material and has a high coercive force.

They have an extremely high energy product range, up to 50 MGOe.

Because of this high product energy level, they can usually be manufactured to be small and compact in size.

However, NdFeB magnets have low mechanical strength, tend to be brittle, and low corrosion-resistance if left uncoated.

If treated with gold, iron, or nickel plating, they can be used in many applications.

They are very strong magnets and are difficult to demagnetize.

Samarium Cobalt (SmCo)

Like NdFeB magnets, SmCo magnets are also very strong and difficult to demagnetize.

They are also highly oxidation-resistant and temperature resistant, withstanding temperatures up to 300 degrees Celsius.

Two different groups of SmCo magnets exist, divided based on their product energy range.

The first series (Sm1Co5) has an energy product range of 15-22 MGOe.

The second series (Sm2Co17) has a range that falls between 22 and 30 MGOe.

However, they can be expensive and have low-mechanical strength.

Alnico

Alnico magnets get their name from the first two letters of each of three main ingredients: aluminum, nickel, and cobalt.

Although they feature good temperature resistance, they can easily be demagnetized and are sometimes replaced by ceramic and rare earth magnets in certain applications.

They can be produced by either sintering or casting, with each process yielding different magnet characteristics.

Sintering produces enhanced mechanical traits.

Casting results in higher energy products and enables the magnets to achieve more complicated design features.

Ceramic or Ferrite

Comprised of sintered iron oxide and barium or strontium carbonate, ceramic or ferrite permanent magnets are typically inexpensive and easily produced, either through sintering or pressing.

However, because these magnets tend to be brittle, they require grinding using a diamond wheel. They are one of the most commonly used types of magnet, and are strong and is not easy to demagnetize.

Temporary Magnets

Temporary magnets can vary in composition, as they are essentially any material that behaves like a permanent magnet when in the presence of a magnetic field.

Soft iron devices, such as paper clips, are often temporary magnets.

Electromagnets

Electromagnets are made by winding a wire into multiple loops around a core material this formation is known as a solenoid.

To magnetize electromagnets, an electrical current is passed through the solenoid to create a magnetic field.

The field is strongest on the inside of the coil, and the strength of the field is proportionate to the number of loops and the strength of the current.

The electromagnet core material at the center of the coil (the core of the solenoid) can also affect the strength of an electromagnet. If a wire is wrapped around a nonmagnetic material, such as a piece of wood, the overall magnetic field will not be very strong.

However, if the core is composed of ferromagnetic material, such as iron, the strength of the magnet will dramatically increase.

So why is an electromagnet classified as a temporary magnet? Because when the power from the battery ceases, so does the current, and the magnetic field disappears.

Applications

Within the industrial sector, magnets are often used as magnetic sweepers, sorters, and to separate impure metals during metal manufacturing or recycling.

In electronic applications, magnets are used in speakers, televisions, telephones, radios, and videotapes.

Typically, electromagnets are used within televisions, computers, and telephones because of their extreme strength.

For this same reason, they are also used in on-off applications, such as cranes used for heavy lifting.

Permanent magnets are perhaps the most common type they are used to manufacture refrigerator magnets, as well as in jewelry making.

Temporary magnets can be useful in applications that generate a temporary magnetic field and require a magnetic response for the duration of the field.

How Does a Permanent Magnet Work?

How a permanent magnet works are all to do with its atomic structure.

All ferromagnetic materials produce a naturally occurring, albeit weak, magnetic field created by the electrons that surround the nuclei of their atoms.

These groups of atoms can orient themselves in the same direction and each of these groups is known as a single magnetic domain.

Like all permanent magnets, each domain has its own north pole and south pole.

When a ferromagnetic material is not magnetized its domains point in random directions and their magnetic fields cancel each other out.

To make a permanent magnet, the ferromagnetic material is heated at incredibly high temperatures, while exposed to a strong, external magnetic field.

This causes the individual magnetic domains within the material to line up with the direction of the external magnetic field to the point when all the domains are aligned and the material reaches its magnetic saturation point.

The material is then cooled and the aligned domains are locked in position.

This alignment of domains makes the magnet anisotropic.

After the external magnetic field is removed hard magnetic materials will keep most of their domains aligned, creating a strong permanent magnet.

Permanent Magnet Strength

There are several measurements that all contribute to a permanent magnet’s strength, which can often seem confusing.

Magnetic field strength (remanence), resistance to demagnetization (coercivity) and pulling force are all often summarised as strength and all are desired attributes of a permanent magnet.

The single primary indicator of a permanent magnet’s strength is its maximum energy product value measured in Mega Gauss Oersteds (MGOe).

The higher the maximum energy product value, the greater the magnetic field the magnet will generate in a particular application.

A maximum energy product, also referred to as BHmax is calculated by multiplying a magnet’s remanence (Br) and coercivity (Hc).

The strongest magnets in the world are neodymium magnets, which are manufactured in different grades, however, each grade is given a handy name that allows you to instantly judge which magnet is stronger.

Commercially available neodymium magnets range from N35 to N52 grade;

the number after the letter ‘N’ represents the magnet’s maximum energy product.

A magnet’s individual performance is altered by temperature and some types of magnets perform better at high temperatures than others, such as alnico and samarium cobalt magnets.

All magnets lose a percentage of their magnetism per ℃ rise in temperature and the five types of magnetic material lose magnetism at different rates and have different maximum operating temperatures.

If the temperature exceeds the maximum operating temperature of the individual grade it will be permanently demagnetized.

Physical Properties

Most permanent magnets are inherently brittle and should not be utilized as structural components.

Dimensions and tolerances vary from manufacturer to manufacturer but most will produce magnets to the tolerance of +/- 0.1mm for all dimensions quoted.

Permanent magnets are produced in many shapes such as standard rings, bars, and discs plus custom shapes such as trapezoid, arc, miter, and even the ‘top hat’.

Permanent magnets are often coated to improve their performance.

Take neodymium magnets, for example, they are the strongest permanent magnets available but they are the most prone to corrosion due to their high iron content, therefore they are virtually always supplied with a coating.

Typical coatings include nickel, stainless steel, PTFE (Teflon), epoxy, rubber, gold, titanium, chrome and many more.

Magnetic Orientation

Permanent magnets can be produced with various magnetic directions.

The term ‘magnetic length’ refers to the dimension of a magnet which follows the

the direction of a magnet’s magnetic axis.

A magnet’s magnetic axis is always listed last when referring to a magnet’s physical dimensions.

The following diagrams show the types of the magnetic direction of permanent magnets.

Oriented Through Thickness

Multi-Pole Segments On Single Face

Axially Oriented In Segments

Magnetism and Electromagnetism

Centuries ago, it was discovered that certain types of mineral rock possessed unusual properties of attraction to the metal iron.

One particular mineral, called lodestone, or magnetite, is found mentioned in very old historical records (about 2500 years ago in Europe, and much earlier in the Far East) as a subject of curiosity.

Later, it was employed in the aid of navigation, as it was found that a piece of this unusual rock would tend to orient itself in a north-south direction if left free to rotate (suspended on a string or on a float in water).

A scientific study undertaken in 1269 by Peter Peregrinus revealed that steel could be similarly “charged” with this unusual property after being rubbed against one of the “poles” of a piece of lodestone.

Unlike electric charges (such as those observed when amber is rubbed against cloth), magnetic objects possessed two poles of the opposite effect, denoted “north” and “south” after their self-orientation to the earth.

As Peregrinus found, it was impossible to isolate one of these poles by itself by cutting a piece of lodestone in half: each resulting piece possessed its own pair of poles:

Like electric charges, there were only two types of poles to be found: north and south (by analogy, positive and negative).

Just as with electric charges, the same poles repel one another, while opposite poles attract.

This force, like that caused by static electricity, extended itself invisibly over space, and could even pass through objects such as paper and wood with little effect upon strength.

The philosopher-scientist Rene Descartes noted that this invisible “field” could be mapped by placing a magnet underneath a flat piece of cloth or wood and sprinkling iron filings on top.

The filings will align themselves with the magnetic field, “mapping” its shape.

The result shows how the field continues unbroken from one pole of a magnet to the other:

As with any kind of field (electric, magnetic, gravitational), the total quantity, or effect, of the field is referred to as a flux, while the “push” causing the flux to form in space is called a force.

Michael Faraday coined the term “tube” to refer to a string of magnetic flux in space (the term “line” is more commonly used now).

Indeed, the measurement of magnetic field flux is often defined in terms of the number of flux lines, although it is doubtful that such fields exist in individual, discrete lines of constant value.

Modern theories of magnetism maintain that a magnetic field is produced by an electric charge in motion, and thus it is theorized that the magnetic field of so-called “permanent” magnets such as lodestone is the result of electrons within the atoms of iron spinning uniformly in the same direction.

Whether or not the electrons in a material’s atoms are subject to this kind of uniform spinning is dictated by the atomic structure of the material (not unlike how electrical conductivity is dictated by the electron binding in a material’s atoms).

Thus, only certain types of substances react with magnetic fields, and even fewer have the ability to permanently sustain a magnetic field.

Iron is one of those types of substances that readily magnetizes.

If a piece of iron is brought near a permanent magnet, the electrons within the atoms in the iron orient their spins to match the magnetic field force produced by the permanent magnet, and the iron becomes “magnetized.” The iron will magnetize in such a way as to incorporate the magnetic flux lines into its shape, which attracts it toward the permanent magnet, no matter which pole of the permanent magnet is offered to the iron:

The previously unmagnetized iron becomes magnetized as it is brought closer to the permanent magnet.

No matter what pole of the permanent magnet is extended toward the iron, the iron will magnetize in such a way as to be attracted toward the magnet:

Referencing the natural magnetic properties of iron (Latin = “Ferrum”), a ferromagnetic material is one that readily magnetizes (its constituent atoms easily orient their electron spins to conform to an external magnetic field force).

All materials are magnetic to some degree, and those that are not considered ferromagnetic (easily magnetized) are classified as either paramagnetic (slightly magnetic) or diamagnetic(tend to exclude magnetic fields).

Of the two, diamagnetic materials are the strongest.

In the presence of an external magnetic field, they actually become slightly magnetized in the opposite direction, so as to repel the external field!

If a ferromagnetic material tends to retain its magnetization after an external field is removed, it is said to have good retentivity.

This, of course, is a necessary quality for a permanent magnet.

REVIEW: Lodestone (also called Magnetite) is a naturally-occurring “permanent” magnet mineral.

By “permanent,” it is meant that the material maintains a magnetic field with no external help.

The characteristic of any magnetic material to do so is called retentivity.

Ferromagnetic materials are easily magnetized.

Paramagnetic materials are magnetized with more difficulty.

Diamagnetic materials actually tend to repel external magnetic fields by magnetizing in the opposite direction.

What Are Some Uses of Permanent Magnets?

There are surprisingly many uses of magnets.

Both permanent magnets, as well as electromagnets, are components in many industrialized products that have a huge influence on our daily lives.

What are some uses of permanent magnets? Permanent magnets are used in hard drives, motors, cars, generators, televisions, phones, headphones, speakers, transducers, sensors, etc.

The most common use of a magnet is the pulling force to attract other magnetic items but it has various functions in electronic tools as well.

That was a very short description of, what you can use a permanent magnet for.

Keep on reading, if you want to know more about the uses of permanent magnets and why it is different compared to an electromagnet.

Later on, we will suggest some creative things you can use permanent magnets for in your daily life.

What are some uses of permanent magnets?

Most people have come across magnets in their kitchen.

Many use permanent magnets on their fridge or maybe on their magnetic knife strip holder.

A permanent magnet has many more uses.

Some of them are listed above as components in electronic devices.

Does a permanent magnet always have the same purpose? To “pin” an object on a magnetic board.

The answer is No! A lot of electronic devices cannot work without magnets.

Without getting too technical, permanent magnets are used in the computer's hard disk drive.

The science behind it uses magnets to help store the information on the disk.

Well, I can’t tell you exactly how that works, but it is one of the many cool and sometimes complex solutions to the use of permanent magnets.

One of the other ones is that it is used in electric motors to turn the electricity in motion.

So if you have an electric toothbrush or a lawnmower, they are also likely to have permanent magnets inside of them as components.

What is a permanent magnet?

You probably know what a magnet is, but what does it mean, that it is permanent? A permanent magnet is made of ferromagnetic materials that have been magnetized.

The reason why its permanent is that it has a persistent magnetic force, that attracts other magnetic objects.

So, a magnet that retains its magnetic properties in the absence of an inducing field or current.

Permanent means lasting or intended to last or remain unchanged indefinitely.

Well, for permanent magnets you measure on their ability of the coercivity.

This is a measurement of how well a magnet withstands an external magnetic field without becoming demagnetized.

The permanent magnets produced today are very resistant to becoming demagnetized, but it is very different compared to which permanent magnet we are talking about.

The strongest magnet on the market is neodymium magnets.

We have written a lot about them in other blog posts, also referred to as Super Magnets or Power Magnets.

These magnets are an alloy of neodymium, iron, and boron.

If they are not demagnetized by extreme heat or other very strong magnets, the force will be almost unchanged for many years, and you will not feel any mentionable difference on your neodymium magnets.

Take care though, they are likely to corrode because of the material.

But how are these permanent magnets created, and what is the difference between them and electromagnets?

Permanent Magnets vs.

Electromagnets

The only magnet you are able to find naturally is called a lodestone.

This is a naturally magnetized piece of the mineral magnetite.

But all the permanent magnets you buy has been refined and is usually an alloy, a combination of different metallic elements.

These elements are mixed together, usually in liquid form, and are manufactured in all kinds of shapes - the objects are afterward magnetized.

The strength depends mostly on materials used, but also the size and shape.

An electromagnet has its magnetic field produced by an electric current.

A simple electromagnet is made from a coil of wire which often is wrapped around a core of ferromagnetic materials like iron.

This means that the magnet only has its properties when an electric current is applied, and you can turn off the magnetic force.

This means it is easier to manipulate the use of an electromagnet by controlling the amount of electric current supplied to it.

The application and utilization of magnets depend on which properties it consists of, so you need to find a magnet that matches your needs.

At MagnetPartner we sell all kinds of different magnets, for different purposes.

Well, it goes without saying, that the fridge magnets are mostly used for “pin” stuff on the fridge.

But we sell all kinds of strong magnets, and we often end a post with a DIY-project for the inspiration of, what else you can use permanent magnets for.

Take a look at our front page, where our six most popular products are shown, and see our categories to the left, which suits the needs of private people as well as institutions and companies.

Our customer service can test the magnets for your needs before you buy anything.

DIY Magnetic Collector

There are many good reasons to make your own ‘Do-it-yourself’ projects.

Some of them are the honor of has done something smart by saving money and the creativity to decide the design yourself.

With today's suggestion, you can definitely save money by creating a magnetic collector yourself.

All you need is a Power Magnet, Ring 15x6x6 MM a string and a plastic bottle.

Tie the string to the magnet, and put the magnet inside the bottle, while holding on to the string.

See how it is done in the video Magnetic-collector .

The language is in Danish, but it has English subtitles.

Now you can hold onto the string while you drag the bottle onto the ground as it collects magnetic materials for example screws and other objects, maybe in your garage or hobby room.

When you have collected the objects on the ground, you can pull up the sting from the bottle, and it will put the objects on the place you need them, maybe in a box - and that is how you make your own magnetic collector.

There are probably different solutions which are just as smart, but this one is very cheap, easy and you can reuse the magnet again for a different DIY-project if you don’t need to the collector again laying around.

Uses of Temporary Magnets and Types of Magnets Examples

Magnet is a material that can attract iron objects and temporary magnets are those which work as a permanent magnet when they are in domain range of permanent magnet attaching to objects and lose their magnetism when they are apart from the permanent magnet.

The magnet attracts objects made of nickel-iron and cobalt and magnet has 2 poles north pole and south pole and opposite poles of two magnets attract each other i.e.

the north pole and south pole and south pole and the north pole of other magnet attract each other and poles of two magnets repel each other and temporary magnets use basically electromagnets are they are useful in many ways in daily life and uses of temporary magnets.

What is temporary Magnets Used For:

The main uses of temporary magnets are used to make temporary electromagnets and let’s see the uses of temporary magnets

The main uses of temporary magnets are used to make temporary electromagnets and let’s see the uses of temporary magnets:

Use of temporary magnets to separate material made of metal in the scrap yard.

Temporary magnets are used in cranes to move magnetic objects from one place to another by lifting up magnets (If it's permanent they do not detach).

Uses of temporary magnets would be paper clips and nails and other soft iron items as examples used for temporary magnets.

Temporary magnets are used in the electromagnet

Temporary magnets are commonly used in electric motors and telephones and speakers.

Temporary magnets are also used to make temporary electromagnets.

Temporary magnets also put a new spin in the modern technology from hi-tech space to high-speed trains.

What is a Magnet Used For:

Magnet is used in daily life in speakers, microphones and from car to a computer magnet are used by harnessing the fundamental force of nature and its power now and magnets on modern levels and magnets are also used in roller coasters.

What Magnets are Important in Our Daily Life:

Magnets are used in credit cards in our daily life.

Magnets are used in Audiotapes.

Magnets are also used in cranes to separate Junk crap magnetic separation.

Bar code systems.

MRI scanning in Medical and also in magnetic therapy.

Uses of Magnet in Battery

Hair Dyer and Motor and use of magnet in daily life

How Many Different Types of Magnets are there?

There are 3 types of magnets:

Temporary Magnets

Electromagnets

How Temporary Magnets are Made?

Temporary magnets are made in two ways stroke method by making a piece of metal like iron nails or the other by the electrical method.

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