MPL 42x20x5 / N38 - lamellar magnet

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They virtually do not lose power, because even after 10 years, the performance loss is only ~1% (according to literature),
• They are very resistant to demagnetization caused by external magnetic fields,
• In other words, due to the glossy nickel coating, the magnet obtains an aesthetic appearance,
• They have very high magnetic induction on the surface of the magnet,
• Neodymium magnets are known for very high magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the geometry),
• The ability for precise shaping and customization to custom needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which amplifies their functionality across industries,
• Important function in new technology industries – they find application in hard drives, electric drives, clinical machines as well as technologically developed systems,
• Compactness – despite their small size, they generate strong force, making them ideal for precision applications

Disadvantages of magnetic elements:

• They are fragile when subjected to a sudden impact. If the magnets are exposed to shocks, it is suggested to place them in a metal holder. The steel housing, in the form of a holder, protects the magnet from fracture while also reinforces its overall durability,
• They lose strength at high temperatures. Most neodymium magnets experience permanent reduction 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 common to use sealed magnets made of synthetic coating for outdoor use,
• The use of a protective casing or external holder is recommended, since machining internal cuts in neodymium magnets is restricted,
• Health risk related to magnet particles may arise, when consumed by mistake, which is crucial in the family environments. Additionally, tiny components from these assemblies can interfere with diagnostics once in the system,
• Due to expensive raw materials, their cost is above average,

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

The given strength of the magnet corresponds to the optimal strength, determined under optimal conditions, specifically:

• with mild steel, used as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a smooth surface
• with zero air gap
• with vertical force applied
• at room temperature

Key elements affecting lifting force

The lifting capacity of a magnet is determined by in practice the following factors, from primary to secondary:

• Air gap between the magnet and the plate, as 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 testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, in contrast under parallel forces the load capacity is reduced by as much as fivefold. Moreover, even a small distance {between} the magnet’s surface and the plate reduces the lifting capacity.