MPL 5x5x1.2 / N38 - lamellar magnet

Strengths and weaknesses of NdFeB magnets.

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

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (in laboratory conditions),
• They have excellent resistance to magnetism drop when exposed to opposing magnetic fields,
• A magnet with a metallic silver surface is more attractive,
• The surface of neodymium magnets generates a maximum magnetic field – this is one of their assets,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Thanks to modularity in forming and the capacity to customize to individual projects,
• Wide application in electronics industry – they are commonly used in hard drives, electric drive systems, advanced medical instruments, as well as complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which enables their usage in miniature devices

Disadvantages of neodymium magnets:

• At very strong impacts they can crack, therefore we recommend placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Limited possibility of creating threads in the magnet and complex forms - recommended is casing - magnet mounting.
• Possible danger to health – tiny shards of magnets are risky, if swallowed, which gains importance in the aspect of protecting the youngest. Furthermore, small components of these devices can be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what it depends on?

Magnet power was defined for ideal contact conditions, assuming:

• using a base made of high-permeability steel, acting as a ideal flux conductor
• whose transverse dimension is min. 10 mm
• characterized by smoothness
• without the slightest air gap between the magnet and steel
• during pulling in a direction vertical to the plane
• at standard ambient temperature

Lifting capacity in real conditions – factors

In practice, the actual holding force is determined by many variables, presented from most significant:

• Distance (between the magnet and the metal), since even a very small distance (e.g. 0.5 mm) results in a reduction in force by up to 50% (this also applies to paint, corrosion or debris).
• Force direction – note that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Steel thickness – insufficiently thick steel causes magnetic saturation, causing part of the flux to be wasted to the other side.
• Metal type – not every steel attracts identically. Alloy additives worsen the attraction effect.
• Smoothness – full contact is possible only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity testing was performed on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, however under parallel forces the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the holding force.