MPL 15x10x2 / N38 - lamellar magnet

Strengths and weaknesses of NdFeB magnets.

Besides their remarkable field intensity, neodymium magnets offer the following advantages:

• They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (based on calculations),
• Magnets very well defend themselves against demagnetization caused by ambient magnetic noise,
• Thanks to the glossy finish, the plating of nickel, gold, or silver gives an elegant appearance,
• Magnets exhibit exceptionally strong magnetic induction on the active area,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and are able to act (depending on the shape) even at a temperature of 230°C or more...
• Thanks to flexibility in constructing and the ability to customize to individual projects,
• Versatile presence in advanced technology sectors – they are used in data components, electric motors, precision medical tools, also other advanced devices.
• Thanks to their power density, small magnets offer high operating force, in miniature format,

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a steel housing, which not only protects them against impacts but also increases their durability
• Neodymium magnets decrease their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore during using outdoors, we advise using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited ability of producing nuts in the magnet and complex shapes - preferred is cover - mounting mechanism.
• Health risk resulting from small fragments of magnets can be dangerous, in case of ingestion, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small components of these magnets are able to disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Highest magnetic holding force – what contributes to it?

Breakaway force was determined for the most favorable conditions, assuming:

• on a base made of mild steel, optimally conducting the magnetic field
• with a thickness no less than 10 mm
• with an polished touching surface
• under conditions of gap-free contact (metal-to-metal)
• for force applied at a right angle (pull-off, not shear)
• at conditions approx. 20°C

Key elements affecting lifting force

Please note that the application force may be lower influenced by elements below, starting with the most relevant:

• Space between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Force direction – remember that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Steel grade – the best choice is high-permeability steel. Cast iron may generate lower lifting capacity.
• Surface finish – full contact is obtained only on polished steel. Rough texture reduce the real contact area, reducing force.
• Thermal environment – heating the magnet results in weakening of force. Check the maximum operating temperature for a given model.

* Lifting capacity was measured using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, however under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet and the plate reduces the holding force.