MP 40x22x10 / N38 - ring magnet
ring magnet
Catalog no 030344
GTIN: 5906301812296
Diameter [±0,1 mm]
40 mm
internal diameter Ø [±0,1 mm]
22 mm
Height [±0,1 mm]
10 mm
Weight
42.41 g
Magnetization Direction
↑ axial
Load capacity
12.54 kg / 122.98 N
Magnetic Induction
139.63 mT
Coating
[NiCuNi] nickel
40.59 ZŁ with VAT / pcs + price for transport
33.00 ZŁ net + 23% VAT / pcs
bulk discounts:
Need more?Hunting for a discount?
Contact us by phone
+48 22 499 98 98
if you prefer send us a note via
inquiry form
through our site.
Force as well as shape of neodymium magnets can be checked with our
magnetic mass calculator.
Same-day shipping for orders placed before 14:00.
MP 40x22x10 / N38 - ring magnet
Magnetic properties of material N38
Physical properties of NdFeB
Shopping tips
Advantages as well as disadvantages of neodymium magnets NdFeB.
Apart from their superior power, neodymium magnets have these key benefits:
- They have constant strength, and over around ten years their attraction force decreases symbolically – ~1% (in testing),
- They show exceptional resistance to demagnetization from external field exposure,
- Thanks to the glossy finish and gold coating, they have an aesthetic appearance,
- They possess significant magnetic force measurable at the magnet’s surface,
- They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
- The ability for custom shaping and adjustment to custom needs – neodymium magnets can be manufactured in many forms and dimensions, which extends the scope of their use cases,
- Wide application in new technology industries – they are used in computer drives, electromechanical systems, diagnostic apparatus along with technologically developed systems,
- Compactness – despite their small size, they generate strong force, making them ideal for precision applications
Disadvantages of NdFeB magnets:
- They are prone to breaking when subjected to a sudden impact. If the magnets are exposed to external force, we recommend in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from fracture and reinforces its overall durability,
- High temperatures may significantly reduce the holding force of neodymium magnets. Typically, above 80°C, they experience permanent deterioration in performance (depending on height). To prevent this, we offer heat-resistant magnets marked [AH], capable of working up to 230°C, which makes them perfect for high-temperature use,
- They rust in a damp environment – during outdoor use, we recommend using moisture-resistant magnets, such as those made of plastic,
- The use of a protective casing or external holder is recommended, since machining threads in neodymium magnets is risky,
- Health risk due to small fragments may arise, when consumed by mistake, which is crucial in the context of child safety. It should also be noted that minuscule fragments from these products may disrupt scanning once in the system,
- High unit cost – neodymium magnets are more expensive than other types of magnets (e.g., ferrite), which may limit large-scale applications
Maximum holding power of the magnet – what affects it?
The given pulling force of the magnet corresponds to the maximum force, measured under optimal conditions, that is:
- with mild steel, serving as a magnetic flux conductor
- of a thickness of at least 10 mm
- with a refined outer layer
- in conditions of no clearance
- under perpendicular detachment force
- at room temperature
Magnet lifting force in use – key factors
The lifting capacity of a magnet is determined by in practice the following factors, ordered from most important to least significant:
- Air gap between the magnet and the plate, since even a very small distance (e.g. 0.5 mm) causes a drop in lifting force of up to 50%.
- Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
- Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
- Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
- Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
- Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.
* Holding force was checked on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 75%. Moreover, even a slight gap {between} the magnet and the plate decreases the holding force.
We Recommend Caution with Neodymium Magnets
Never bring neodymium magnets close to a phone and GPS.
Magnetic fields can interfere with compasses and magnetometers used in aviation and maritime navigation, as well as internal compasses of smartphones and GPS devices. There are neodymium magnets in every smartphone, for example, in the microphone and speakers.
People with pacemakers are advised to avoid neodymium magnets.
Neodymium magnets produce strong magnetic fields that can interfere with the operation of a heart pacemaker. Even if the magnetic field does not affect the device, it can damage its components or deactivate the entire device.
Keep neodymium magnets away from TV, wallet, and computer HDD.
Strong fields generated by neodymium magnets can damage magnetic storage media such as floppy disks, credit cards, magnetic ID cards, cassette tapes, video tapes, or other similar devices. They can also damage televisions, VCRs, computer monitors, and CRT displays. Avoid placing neodymium magnets in close proximity to electronic devices.
Dust and powder from neodymium magnets are flammable.
Avoid drilling or mechanical processing of neodymium magnets. If the magnet is crushed into fine powder or dust, it becomes highly flammable.
Neodymium magnets can attract to each other due to their immense internal force, causing the skin and other body parts to get pinched and resulting in significant injuries.
Magnets will crack or alternatively crumble with uncontrolled joining to each other. Remember not to approach them to each other or hold them firmly in hands at a distance less than 10 cm.
The magnet is coated with nickel - be careful if you have an allergy.
Studies show a small percentage of people have allergies to certain metals, including nickel. An allergic reaction often manifests as skin redness and rash. If you have a nickel allergy, try wearing gloves or avoid direct contact with nickel-plated neodymium magnets.
Magnets made of neodymium are highly susceptible to damage, resulting in their cracking.
Neodymium magnets are characterized by considerable fragility. Neodymium magnets are made of metal and coated with a shiny nickel surface, but they are not as hard as steel. In the event of a collision between two magnets, there may be a scattering of fragments in different directions. Protecting your eyes is crucial in such a situation.
Neodymium magnets can become demagnetized at high temperatures.
In certain circumstances, Neodymium magnets may experience demagnetization when subjected to high temperatures.
Neodymium magnets are among the most powerful magnets on Earth. The astonishing force they generate between each other can shock you.
Make sure to review all the information we have provided. This will help you avoid harm to your body and damage to the magnets.
Magnets are not toys, children should not play with them.
Neodymium magnets are not toys. You cannot allow them to become toys for children. In the case of small magnets, they can be swallowed and cause choking. In such cases, the only solution is to undergo surgery to remove the magnets, and otherwise, it can even lead to death.
Be careful!
Please see the article - What danger lies in neodymium magnets? You will learn how to handle them properly.