UMT 12x20 purple / N38 - board holder

Advantages and disadvantages of neodymium magnets NdFeB.

Apart from their strong magnetism, neodymium magnets have these key benefits:

• They do not lose their strength nearly 10 years – the decrease of lifting capacity is only ~1% (theoretically),
• They protect against demagnetization induced by ambient electromagnetic environments remarkably well,
• In other words, due to the shiny gold coating, the magnet obtains an stylish appearance,
• Magnetic induction on the surface of these magnets is impressively powerful,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• The ability for precise shaping as well as adaptation to specific needs – neodymium magnets can be manufactured in multiple variants of geometries, which amplifies their functionality across industries,
• Significant impact in cutting-edge sectors – they find application in data storage devices, electric drives, medical equipment or even technologically developed systems,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of magnetic elements:

• They are prone to breaking when subjected to a powerful impact. If the magnets are exposed to physical collisions, we recommend in a steel housing. The steel housing, in the form of a holder, protects the magnet from cracks , and at the same time strengthens its overall strength,
• They lose field intensity at elevated temperatures. Most neodymium magnets experience permanent degradation in strength when heated above 80°C (depending on the form and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Due to corrosion risk in humid conditions, it is wise to use sealed magnets made of rubber for outdoor use,
• Limited ability to create threads in the magnet – the use of a housing is recommended,
• Possible threat due to small fragments may arise, especially if swallowed, which is important in the context of child safety. It should also be noted that minuscule fragments from these devices might hinder health screening if inside the body,
• In cases of tight budgets, neodymium magnet cost may not be economically viable,

Maximum lifting force for a neodymium magnet – what contributes to it?

The given lifting capacity of the magnet means the maximum lifting force, measured under optimal conditions, namely:

• with mild steel, used as a magnetic flux conductor
• with a thickness of minimum 10 mm
• with a smooth surface
• with no separation
• with vertical force applied
• in normal thermal conditions

Impact of factors on magnetic holding capacity in practice

Practical lifting force is dependent on elements, listed from the most critical to the less 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.

* Lifting capacity testing was conducted on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, however under shearing force the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate decreases the load capacity.