MPL 40x10x4 / N38 - lamellar magnet

Advantages as well as disadvantages of NdFeB magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• Their magnetic field remains stable, and after around ten years it drops only by ~1% (according to research),
• They do not lose their magnetic properties even under external field action,
• Thanks to the elegant finish, the surface of Ni-Cu-Ni, gold, or silver gives an aesthetic appearance,
• Neodymium magnets deliver maximum magnetic induction on a small area, which ensures high operational effectiveness,
• Thanks to resistance to high temperature, they are capable of working (depending on the shape) even at temperatures up to 230°C and higher...
• Thanks to freedom in designing and the ability to customize to specific needs,
• Huge importance in modern technologies – they find application in hard drives, brushless drives, medical equipment, as well as technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which allows their use in small systems

Cons of neodymium magnets and proposals for their use:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also improves its resistance to damage
• When exposed to high temperature, neodymium magnets suffer a drop in strength. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend casing - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complicated forms.
• Potential hazard related to microscopic parts of magnets are risky, in case of ingestion, which gains importance in the context of child health protection. Furthermore, small elements of these devices can complicate diagnosis medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Magnetic strength at its maximum – what contributes to it?

The declared magnet strength represents the maximum value, obtained under laboratory conditions, meaning:

• with the application of a yoke made of special test steel, guaranteeing full magnetic saturation
• with a thickness no less than 10 mm
• characterized by lack of roughness
• under conditions of no distance (surface-to-surface)
• for force acting at a right angle (in the magnet axis)
• at temperature room level

Lifting capacity in practice – influencing factors

Effective lifting capacity is affected by specific conditions, mainly (from priority):

• Space between magnet and steel – every millimeter of separation (caused e.g. by varnish or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is obtained only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is typically many times smaller (approx. 1/5 of the lifting capacity).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of generating force.
• Material composition – not every steel attracts identically. Alloy additives worsen the attraction effect.
• Base smoothness – the more even the surface, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Thermal environment – temperature increase causes a temporary drop of induction. Check the thermal limit for a given model.

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under a perpendicular pulling force, however under shearing force the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate decreases the lifting capacity.