MPL 5x5x1.5 / N38 - lamellar magnet

Advantages and disadvantages of neodymium magnets NdFeB.

Apart from their consistent holding force, neodymium magnets have these key benefits:

• They have stable power, and over nearly ten years their performance decreases symbolically – ~1% (in testing),
• They are extremely resistant to demagnetization caused by external magnetic fields,
• Because of the reflective layer of gold, the component looks high-end,
• 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 precise shaping and customization to specific needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which amplifies their functionality across industries,
• Key role in new technology industries – they serve a purpose in hard drives, electric motors, clinical machines or even sophisticated instruments,
• Thanks to their power density, small magnets offer high magnetic performance, in miniature format,

Disadvantages of rare earth magnets:

• They are fragile when subjected to a powerful impact. If the magnets are exposed to external force, we recommend in a steel housing. The steel housing, in the form of a holder, protects the magnet from fracture while also reinforces its overall durability,
• They lose magnetic force at high temperatures. Most neodymium magnets experience permanent degradation in strength when heated above 80°C (depending on the shape and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• They rust in a damp environment. For outdoor use, we recommend using encapsulated magnets, such as those made of plastic,
• Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing threads directly in the magnet,
• Possible threat linked to microscopic shards may arise, if ingested accidentally, which is important in the protection of children. Furthermore, minuscule fragments from these magnets have the potential to hinder health screening if inside the body,
• In cases of tight budgets, neodymium magnet cost may be a barrier,

Best holding force of the magnet in ideal parameters – what it depends on?

The given lifting capacity of the magnet represents the maximum lifting force, calculated under optimal conditions, specifically:

• with mild steel, serving as a magnetic flux conductor
• having a thickness of no less than 10 millimeters
• with a smooth surface
• with zero air gap
• with vertical force applied
• in normal thermal conditions

Determinants of lifting force in real conditions

Practical lifting force is determined by factors, listed from the most critical to the less significant:

• Air gap between the magnet and the plate, because even a very small distance (e.g. 0.5 mm) can cause 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 was determined by applying a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, however under attempts to slide the magnet the load capacity is reduced by as much as 75%. Additionally, even a minimal clearance {between} the magnet and the plate reduces the load capacity.