How Long does a Magnet Last : We are frequently asked about the shelf life of permanent magnets and the lifespan of neodymium magnets.
The simple answer is no, there is no shelf life; however, as with all things magnet-related, it is not that simple.
How Long does a Magnet Last
The short Answer:
A permanent magnet, if stored and used properly, will retain its magnetism for many years.
A neodymium magnet, for example, is estimated to lose about 5% of its magnetism every 100 years.
The magnet should not be subjected to temperatures above its maximum operating temperature, it should be protected from corrosion, and it should not be subjected to strong demagnetising fields.
What is the lifespan of a neodymium magnet?
Neodymium magnets are permanent magnets that lose a fraction of their performance every 100 years if kept in optimum working conditions.
A magnet’s lifespan can be reduced by two factors.
If a magnet’s temperature exceeds its maximum operating temperature (e.g., 80oC for N42 grade neodymium magnets), it will lose magnetism that will not be recovered upon cooling.
Samarium cobalt magnets are not as strong as neodymium magnets, but they can operate at temperatures of up to 350 degrees Celsius.
If the plating on a magnet is damaged and water gets inside, the magnet will rust, resulting in a decrease in magnetic performance.
Samarium cobalt magnets and ferrite magnets are both corrosion resistant, but not as strong as neodymium magnets.
A product’s shelf life indicates when it can no longer perform its intended function, or when it becomes unhealthy or dangerous.
To be unable to perform its intended function, a permanent magnet must lose some or all of its ability to generate a net external field.
The magnitude of this loss would determine the magnet’s ability to function.
So, if a magnet is left alone on a shelf with no external influences, only “Magnetic Creep” has the potential to reduce the magnet’s field.
When a magnet begins to yield to self-demagnetizing forces, this is referred to as “Magnetic Creep.”
In general, it takes a long time to realize even minor changes in a well-designed magnet that is not subjected to any other stresses.
What exactly is a long time?
Depending on the magnetic alloy, this can range from years to decades.
Magnets, on the other hand, must be stored, handled, packaged, counted, and so on in the real world, and they may be subjected to other negative factors.
What factors would a magnet encounter in storage that would impair its ability to generate a net field?
Heat Volume Loss, Volume Loss, and External Demagnetizing Fields
Volume loss is the most noticeable factor, which could be caused by corrosion or impacts in which actual chips or portions of the magnet are removed.
The field produced by a smaller magnet is less powerful.
Magnets must be protected not only in their intended application, but also during storage.
To avoid corrosion, keep the magnets in a clean, dry environment.
It is preferable to keep them in the packaging provided by the magnet vendor.
Magnets are frequently supplied attracting in rows, sometimes with spacers.
The magnets should also be kept in this vendor-supplied configuration to eliminate the possibility of volume loss due to chipping during handling.
External Demagnetizing Fields
A very strong magnetic field magnetizes permanent magnets.
Magnets may occasionally come into contact with magnetic fields emitted by other magnets, which can be harmful.
This is especially true when magnets with multiple part numbers are stored in the same location.
Larger, more powerful magnets can produce a field that partially demagnetizes smaller magnets.
Certain magnet alloys are more prone to this.
The most vulnerable alloys are Alnico (Aluminum Nickel Cobalt) and Ceramic (Strontium Ferrite) grades.
Steps to reduce the effects of external magnetic fields:
- Keep the magnets in the packaging provided by the vendor.
- Continue to attract the magnets in a row, and where the rows are attracting
- Separate packages and dunnage of unlike magnets.
The table below depicts the general tolerances of commonly used commercial magnet alloys to corrosion, impacts, and external magnetic fields.
|Neodymium Iron Boron||High||Medium||Low|
|Samarium Cobalt||Low||High||Very Low|
|Alnico (Aluminum Nickel Cobalt)||Very Low||*Medium to Low||*Medium to High|
|Ceramic (Strontium Ferrite)||Very Low||Medium||Medium|
Heat will always have an effect on permanent magnets, but most storage and transportation methods will never reach a high enough temperature to cause irreversible magnet loss.
High temperatures, on the other hand, will hasten the negative effects of corrosion and demagnetizing fields.
Magnets should be stored in an environment that a human would find comfortable.
What factors can degrade a magnet’s performance?
All magnets have a ‘pull’ rating in kilograms that describes how much force acting perpendicular to the magnet is required to pull the magnet from a steel plate or equal thickness when in direct, flush contact.
The ‘pull’ rating is obtained under the ideal conditions listed below:
– the test bed steel plate is thick enough to absorb all of the magnetism (typically 10mm thick); – it is clean and perfectly flat; – the pulling force is gradually and steadily increased; and – it is perpendicular to the magnet face.
Perfect conditions are unlikely in real-world applications, and the following factors will reduce the given pull:
Thickness of steel
If a magnet requires a 10mm thick contact steel surface to absorb all of the magnetism and deliver maximum pull, then fixing the magnet to a 1mm thick sheet steel surface will waste 90% of the magnetism and deliver only 10% of its capability.
To see if the contact steel is thick enough to absorb all of the magnetism from a given magnet, simply place the magnet in place and then place a small steel plate behind the contact steel, directly behind the magnet; if it sticks, it is being held in place by stray magnetism escaping from insufficiently thick steel.
If it falls away, the contact steel absorbs and conducts all of the magnetism, and increasing the thickness of the steel will not increase the magnet’s ‘pull.’
There is an air gap.
If the contact steel is rusted, painted, or uneven, the resulting gap between the magnet and the contact steel reduces the magnet’s ‘pull.’
The pull decreases as the gap widens, according to an inverse square law relationship.
As a contact steel, mild steel is used in all pull tests.
Alloy steels and cast irons have a reduced ability to conduct magnetism, resulting in a weaker magnetic pull.
Because cast iron is much less permeable than mild steel, the pull will be reduced by up to 40% in this case.
When a magnet is exposed to temperatures above its maximum operating temperature, it loses performance that cannot be recovered by cooling.
Heating above the maximum operating temperature repeatedly will result in a significant decrease in performance.
It is five times easier to slide a magnet than it is to pull it vertically away from the surface to which it is attracted.
This is entirely due to the coefficient of friction, which for steel on steel faces is typically 0.2.
If magnets with a rated pull of 10kg are used on a vertical steel wall and the load causes the magnets to slide down the wall, they will only support 2kg.
Which magnets are best suited for use by children?
When playing with magnets, children should always be supervised.
Neodymium magnets are too powerful for children, and small neodymium magnets are extremely dangerous if swallowed by a child, as they can attract in the intestines, necessitating immediate surgery.
Small alnico magnets are strong enough for children to experiment with magnetism without risking finger trapping.
Traditional alnico horseshoe magnets and educational alnico bar magnets, for example, are widely used in schools throughout the United Kingdom.
These magnets are also available in sets with iron filings to demonstrate the invisible magnetic fields: horseshoe set – bar magnet set.
Are magnets harmful to people who have pacemakers?
The close proximity of a magnet will affect the operation of heart pacemakers because it can cause pacemakers to operate in a mode that does not respond to the user’s own heart rhythm.
Because the way a pacemaker responds to a magnetic field varies by manufacturer, people who have pacemakers should avoid putting strong magnets near their chest.
Will a magnet harm my phone or tablet?
Small and medium-sized magnets should have no negative impact on your smartphone or tablet.
It’s possible that these devices already have small magnets that allow them to perform specific functions.
Large, powerful magnets, on the other hand, should be kept away from any electronic device because strong magnetic fields can damage mechanical parts.
Will a magnet cause harm to my wristwatch?
If the tiny components of mechanical wrist watches are made of ferrous material, they can become magnetized when placed in close proximity to strong magnetic fields.
If the mechanical ferrous parts become magnetized, they can attract to each other, to the inside of the casing, causing the watch to run faster or slower, or to stop working entirely.
Many modern watches are now made of ‘non-magnetic’ materials, making them resistant to relatively weak magnetic fields.
To be safe, keep your mechanical watch away from strong magnetic fields at all times.
If your watch becomes magnetized, a watch repair shop should be able to demagnetize it and restore it to working order.
What exactly is the distinction between a permanent magnet and an electromagnet?
A permanent magnet is a solid material that, because it is magnetized, generates its own consistent magnetic field.
Unlike permanent magnets, an electromagnet’s magnetic field is created by the flow of electric current.
When the current is turned off, the magnetic field vanishes.
An electromagnet is typically made up of many turns of copper wire that form a solenoid.
A magnetic field is created when an electric current flows around the solenoid coil.
When an iron core is inserted into the bore of this solenoid, magnetism is induced and it becomes magnetic; however, when the current is turned off, it immediately becomes nonmagnetic.
What materials are permanent magnets made of?
Modern permanent magnets are classified into five types, each made of a different material with unique properties.
The most powerful magnets, known as rare earth magnets, are neodymium magnets made from an alloy of neodymium, iron, and boron (NdFeb) and samarium cobalt magnets made from samarium, cobalt, and small amounts of iron, copper, and other materials.
Other types of permanent magnets include ferrite magnets, which are made of a ceramic material and iron oxide (SrO.6Fe2O3), and alnico magnets, which are made of aluminum, nickel, and cobalt, as well as flexible rubber.
What exactly are magnetic poles?
The poles of a magnet are the surfaces from which lines of magnetism leave the magnet and reconnect when they return to the magnet.
A magnet’s pole is the area with the greatest magnetic field strength in a given direction.
Each pole is oriented either north or south.
If you split a magnet in half, each half still has a north pole and a south pole.
A magnet, no matter how small, will always have a north pole and a south pole.
Contrary to popular belief, there is no such thing as a monopole magnet.
Which magnet pole should I use?
A magnet’s north pole and south pole have equal holding power and will both stick to magnetic material such as steel or iron.
Like poles (e.g., north facing north or south facing south) of two magnets will always repel each other, whereas opposite poles (e.g., north facing south or south facing north) will always attract.
Self-adhesive and countersunk magnets with either pole on the magnetic face are available from us.
How do I determine the poles of a magnet?
The simplest way to identify the poles of a magnet is to use a compass or an analogue or digital pole identifier.
If you have a smartphone, you can also use our Virtual Pole Tester app to determine the polarity of a magnet pointing at your phone.
When identifying the pole of a magnet with a compass, keep in mind that the north pole of a magnet points towards the Earth’s geographic North Pole, which is actually close to the Earth’s magnetic south pole.
This is why, when you hold a compass to a magnet, the needle will point to the south pole, following the rule that like poles repel and opposite poles attract.
What is the most effective way to observe a magnetic field?
Iron powder and filings are ideal for sprinkling onto an A4 sheet of paper to demonstrate the magnetic field lines produced by a magnet.
Simply place the magnet beneath the paper and observe how the filings move around to reveal the magnetic field lines of any given magnet.
Magnet accessories for schools and universities that we recommend are iron powder and filings.
See our entire selection in our Science and education magnets section, or try our horseshoe and bar magnet sets.
What exactly are rare earth magnets?
Rare earth magnets are known for their strength and are made from the periodic table’s rare earth group of elements.
The most common types are neodymium-iron-boron (NdFeb) and samarium cobalt (SmCo).
Despite their name, rare earth elements are relatively abundant in the earth’s crust; however, they are rarely found in economically exploitable deposits and are frequently dispersed, hence the term “rare earth.”
What does a neodymium magnet’s “N rating” mean?
There are numerous commercially available grades of neodymium, ranging from N35 to N55, as well as other high-temperature variations.
The ‘N’ grade refers to the magnet’s maximum energy product, which is a measure of its strength.
An N35 neodymium magnet, for example, has a maximum energy product of 35 Mega-Gauss Oersted (MGOe), while a N55 has a maximum energy product of 55 MGOe.
In general, the higher the grade, the stronger the magnet.
Variations of the ‘N’ rating with one or two letters following the number denote high-temperature grades, each with a different maximum operating temperature.
Can I use adhesive to hold magnets in place, and if so, what kind should I use?
The majority of magnets can be bonded in place using two-part epoxy adhesives.
Araldite Rapid, which hardens in about 5 minutes, is our recommendation.
Loctite Industrial Strength Adhesive, which has a similar setting time, is also recommended.
With the exception of certain polythene-type plastics, both have a proven track record of reliably bonding magnets to most surfaces.
Is it possible to cut or drill a magnet?
You should never try to cut or drill a magnet because the manufacturing process makes most magnets (except flexible magnets) very hard and brittle.
Because the dust is flammable, these magnets cannot be drilled with HSS or even carbide drills; they must be drilled or cut with diamond tooling and plenty of coolant.
Because the grindings are magnetic, within a few seconds of drilling, the entire magnet will resemble a hedgehog due to the grindings’ attraction to the magnet.
It is far better to specify a hole that can be machined and magnetized later.
How are magnets created?
Each type of permanent magnet is made differently, but they all involve casting, pressing and sintering, compression bonding, injection molding, extruding, or calendaring processes.
What is the mechanism of a magnet?
The atomic structure of a permanent magnet determines how it works.
The electrons that surround the nuclei of their atoms create a naturally occurring, albeit weak, magnetic field in all ferromagnetic materials.
These atom groups can orient themselves in the same direction, and each of these groups is referred to as a single magnetic domain.
Each domain, like all permanent magnets, has its own north and south poles.
When a ferromagnetic material is not magnetized, its domains point in random directions, and their magnetic fields cancel out.
To create a permanent magnet, ferromagnetic material is heated to extremely high temperatures while being subjected to a strong external magnetic field.
This causes the material’s individual magnetic domains to align with the direction of the external magnetic field until all domains are aligned and the material reaches its magnetic saturation point.
After that, the material is cooled and the aligned domains are locked in place.
Because of the domain alignment, the magnet is anisotropic.
When the external magnetic field is removed, hard magnetic materials retain the majority of their domains, resulting in a strong permanent magnet.
What exactly is the distinction between anisotropic and isotropic magnets?
Most modern magnets are made with a preferred magnetism direction, indicating that they are anisotropic.
An anisotropic magnet is one in which all of its individual atomic magnetic domains are aligned in the same direction.
This is accomplished during the manufacturing process in order to provide maximum magnetic output.
This is known as the magnetic axis.
At a critical point during the manufacturing process, each magnet is subjected to a strong electromagnetic field, which ‘locks’ the domains parallel to the applied electromagnetic field.
An anisotropic magnet can only be magnetized in the direction (along its magnetic axis) that was determined during manufacturing.
Attempts to magnetize the magnet in any other direction yield no magnetism.
A magnet made of magnetically isotropic material has no preferred magnetism direction and the same properties along either axis.
Isotropic material can be manipulated during manufacturing so that the magnetic field can be applied in any direction.
Anisotropic magnets are far more powerful than isotropic magnets, which have randomly oriented magnetic domains and thus produce far less magnetism.
Isotropic magnets, on the other hand, have the advantage of being magnetized in any direction.
What exactly is Gauss?
Gauss is both a magnetic induction measure and a density value.
Simply put, a magnet’s Gauss measurement represents the number of magnetic field lines emitted by a magnet per square centimetre.
The higher the value, the more lines of magnetism emitted by a magnet; however, this alone is not a representation of a magnet’s strength.
Geometry, in addition to material, influences a magnet’s Gauss value. For example, if you have two different sized magnets made of the same material with the same surface Gauss, the larger magnet will always be stronger.
A small magnet with a high surface Gauss may be able to support more weight than a larger magnet with a lower surface Gauss.
If a neodymium magnet has a Br measurement of 13,800 Gauss.
Will 13,800 Gauss be measured on the surface of the magnet?
No, the Br value, also known as remanence, is the theoretical maximum density of a magnetic field within a magnet when used in closed circuit conditions.
Magnets rarely exceed 7,000 Gauss in open circuit conditions.
The surface Gauss value of an open circuit (not connected to any other ferrous object) magnet is the density of the magnetic field at any point on the magnet’s surface.
A 25mm diameter by 20mm thick N52 neodymium magnet, for example, made from one of the strongest magnetic materials commercially available, will measure a maximum of 6,250 Gauss on its surface and significantly less as you move away from it.
What does it mean to be ‘diametrically magnetised’?
Some of our disc, rod, and ring magnets are diametrically magnetised, which means that instead of the north and south poles being on opposite flat faces, the north pole is on one curved side and the south pole on the other.
Diametrically magnetised magnets are frequently used to provide rotational movement rather than to hold the maximum possible weight for the size of the magnet.
Which materials are suitable for blocking/shielding magnetic fields?
Magnetic fields can pass through plastic, wood, aluminum, and even lead as if they were not present.
There is no material that can prevent magnetism.
Magnetic fields can be conducted and redirected by ferrous materials such as iron, steel, or nickel.
All magnetic fields seek the shortest path from north to south, and a piece of steel can provide a shortcut that makes the journey much easier than flowing through air.
To remove magnetism from places you don’t want it, use steel to provide a shortcut for the magnet to redirect the magnetism flow via an alternate route.
The most basic example is to place a steel keeper across the poles of a horseshoe magnet; all of the magnetism flows through the steel and there is no external magnetic field.
The airlines require that there be no magnetism on the outside of the box when we send highly magnetized materials overseas.
To accomplish this, we place the magnets in the center of the box and then line the inside of the box with steel sheets on all six sides.
Stray magnetism that would normally pass through the box’s walls is abruptly diverted as it conducts through the steel on its journey from north to south.
Is it true that stacking magnets makes them stronger?
Using two magnets together would be equivalent to having one magnet of the same size.
For example, stacking two 10mm diameter x 2mm thick magnets on top of each other would result in a 10mm diameter x 4mm thick magnet, effectively doubling the magnet’s strength and pull.
Once the length of the magnet exceeds the diameter of the magnet, the magnet is operating at peak performance, and further increases in magnetic length will result in only minor improvements in performance.
Can I increase the strength of an existing magnet?
Once a magnet has been fully magnetised, it cannot be made any stronger because it has been fully ‘saturated’.
It’s like a full bucket of water; once it’s full to the brim, it can’t be filled any further.
By stacking one magnet on top of another, the stacked magnets will function as one larger magnet with greater magnetic performance.
As more magnets are stacked together, the strength increases until the stack’s length equals the diameter.
Any additional magnets added after this point will provide a negligible improvement in performance.
Where is the strongest magnetic pull on a magnet?
Any magnet’s magnetic field is always strongest at either pole.
The magnetic force is the same at both the north and south poles.
Is the total attracting force equal to the sum of the individual pull forces of each magnet if I use two magnets to attract to each other?
Although the logical assumption would be that when two magnets are used together, the attracting force is equal to the sum of both individual pull forces, this is not the case.
While the total combined attracting force will be slightly increased, it will still fall short of the total combined value.
Is it possible to attract an object from a distance using magnets?
The ability of a magnet to attract/repel decreases significantly when it is not in direct, flush contact with a steel surface or another magnet.
The amount is roughly exponential; however, each shape and size of magnet is unique.
All of our magnets are tested in direct contact with a steel plate and through a series of ‘air gaps’ ranging from 0.1mm to 20mm.
How is a magnet’s strength determined?
There are several terms used to describe a magnet’s strength, including:
Pull – The amount of force required to pull the magnet away from a steel surface, usually expressed in kilograms.
Gauss reading (flux density) – By placing a Gauss meter or flux meter hall probe on the pole of a magnet, a reading of the number of lines of magnetism in every cm2 (1 Gauss = 1 line of magnetism in 1cm2), also known as flux density, can be obtained.
This reading is a ‘open circuit’ value, which will be significantly lower than the Br value and will be directly related to the magnet’s material and length to diameter ratio.
Even if they are made of the same grade of magnetic material, long magnets with small diameters will have a much higher open circuit flux density than short magnets with relatively large diameters.
If you took a 5,000 Gauss rod magnet and cut it in half, you would not expect the two smaller length magnets to have the same Gauss reading in open circuit.
Testing for hysteresis graphs – This is a thorough test in which the magnet is magnetized and demagnetized in a closed circuit situation and values for Br, Hc, and (BH)max are obtained.
These are the maximum amount of magnetism in a closed circuit magnet, the resistance to demagnetization, and the total energy contained within the magnet.
What is the most powerful type of magnet?
Rare earth neodymium magnets are the strongest commercially available magnets.
They are also known as NdFeb magnets because they are made of a neodymium, iron, and boron alloy.
They are available in a variety of grades, the strongest of which is N55.
What exactly is ferrofluid?
Ferrofluid is a magnetic field-reactive liquid composed of tiny magnetic particles coated with a stabilizing dispersing agent and suspended in a carrier liquid.
Even when a strong magnetic field is applied to the liquid, the dispersing agent, known as a surfactant, prevents the tiny magnetic particles from clumping together.
When an external magnetic field is applied, the particles, which behave like spherical magnets with north and south poles, experience torque and align themselves in the direction of the magnetic field.
The fluid forms amazing spikes as a result of this reaction, which can be precisely controlled by applying and removing a magnetic field, such as that produced by a neodymium magnet.
Ferrofluid is truly a marvel to behold and makes a truly one-of-a-kind gift.
How should ferrofluid be disposed of?
Ferrofluid is non-toxic, and in small amounts, it can be disposed of in the same manner as motor oil.
Our recommendation is to place it in a sealed container, such as an old jam jar, and take it to your local waste recycling dump.
What is the tensile strength of flexible magnetic tape and sheet?
In small quantities, flexible magnetic tapes and sheets are not as strong as hard permanent magnets; however, when used over a large surface area, they can be extremely effective.
Flexible magnetic tape or sheet typically has a pulling force of 40 grams per cm2 and can be a low-cost solution for hanging signs and displays.
Can I use other types of permanent magnets to adhere to flexible magnet sheet or tape?
Unfortunately, because other types of magnets have higher magnetic performance, such as neodymium or ferrite, they will actually damage the magnetic sheeting by realigning the magnetic particles in the sheet.
As a result, the sheet will be significantly weakened in the area(s) where the magnets have been placed.
You should use a ferrous sheet or tape if you want to use a flexible sheet with neodymium magnets.
While ferrous sheet or tape does not generate any magnetism of its own, it is excellent for sticking magnets.
Do you have the ability to cut your flexible sheet and tape magnets?
Trimmers or household scissors can be used to cut all of our flexible sheet and tape magnets.
To see our entire selection of flexible magnets, please visit our ‘Flexible Magnets’ section.
Is it possible to print on your flexible sheet and tape magnets?
We can provide flexible magnetic sheet and tape that are laminated with coloured vinyl and are ideal for screen printing, digital printing, or laminating vinyl graphics onto at first4magnets.com.
Can you provide monopole magnets?
Magnetism flows from a magnet’s north pole to its south pole; if a magnet only had one pole, there would be no magnetism and thus the magnet could not exist.
As a result, monopole magnets do not exist.
Every magnet has a north and a south pole.
If you take a bar magnet with a north pole at one end and a south pole at the other and cut it in half to secure just a north pole, you will notice that the two halves now have a north and south pole as well.
If a monopole could be created, it would allow for perpetual motion magnet generators, which would result in infinite free electricity.
Which magnets are appropriate for magnetic therapy?
We do not have any scientific evidence to support the theory that magnets and magnetic fields provide therapeutic benefits and pain relief at first4magnets.
Despite this, we have been contacted by a number of customers who have purchased our magnets and are pleased with the results.
What are the best magnets for making fridge magnets?
In general, fridge magnets purchased from gift or souvenir shops will have a flexible rubber or ferrite magnet on the back.
Both types of magnets offer excellent value for money.
While not as powerful as neodymium magnets, they are powerful enough to hold a lightweight item to a refrigerator.
Both flexible rubber and ferrite magnets have self-adhesive on one side and are ideal for making your own fridge magnets.
Which magnets are ideal for use on glass wipe boards?
Because there is a thick sheet of glass between the magnet and the magnetic surface on glass wipe boards, most magnets that are suitable for normal whiteboards simply fall off because they lack the required depth of field to deal with the thickness of glass.
Which magnets can be used with magnetic plaster?
This is dependent on what you’re attempting to hold.
If you want to hang something lightweight, such as photos or posters, our noticeboard magnets are ideal, or small self-adhesive magnets can be stuck to the back of the item you want to hang.
If you need to hold picture frames or other similar items, our high-powered magnetic sheet or magnetic tape should suffice.
Our rubber-coated pot magnets are the best solution for heavier items because the rubber increases the magnet’s slide resistance.
If the item to be hung is sliding down the wall, add cut pieces of our high-power flexible magnetic sheet to increase friction between the item and the wall.
- For example, it is estimated that a neodymium magnet loses approximately 5% of its magnetism every 100 years.
- In the case of cast iron, the pull will reduce by as much as 40% because cast iron is much less permeable than mild steel. (first4magnets.com)
- Any metal could be ripped out by the immensely powerful, 10.5-tesla magnet weighing almost 3 times more than a Boeing 737 aeroplane and a full 50% more powerful than the strongest magnets approved for clinical use. (nature.com)
- You’re not alone more than 75 percent of women have hot flashes at some point in their lives. (healthline.com)
- Your permanent magnet should lose no more than 1% of its magnetic strength over a period of 100 years provided it is specified and cared for properly. (mpimagnet.com)
- Since ferrite magnets are permanent magnets, they will only lose less than 10 percent of their magnetism every 100 years.
- What Ferrite Magnets Are Made Of: Chemical Compound Ferrite Chemical Composition SrO6(Fe2O3) 90 percent iron oxide
- Made up mostly of iron oxide, this element accounts for about 90 percent of the entire makeup of the magnet.
- The strontium carbonate, on the other hand, will only make up around 10 percent of the average ferrite magnet. (magnetpartner.com)