MW 5x30 / N38 - cylindrical magnet

Pros as well as cons of NdFeB magnets.

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

• Their power is durable, and after approximately ten years it drops only by ~1% (theoretically),
• Magnets perfectly protect themselves against loss of magnetization caused by external fields,
• Thanks to the elegant finish, the surface of nickel, gold, or silver gives an aesthetic appearance,
• The surface of neodymium magnets generates a powerful magnetic field – this is one of their assets,
• Due to their exceptional temperature resistance, they can operate (depending on the geometry) even at temperatures up to 230°C or more,
• Thanks to freedom in shaping and the ability to adapt to specific needs,
• Fundamental importance in high-tech industry – they are commonly used in hard drives, drive modules, diagnostic systems, also technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are prone to damage upon too strong 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
• 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 nuts in the magnet and complex forms - preferred is casing - mounting mechanism.
• Health risk related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the aspect of protecting the youngest. Furthermore, tiny parts of these magnets can disrupt the diagnostic process medical after entering the body.
• With budget limitations the cost of neodymium magnets is economically unviable,

Maximum magnetic pulling force – what it depends on?

The lifting capacity listed is a theoretical maximum value performed under standard conditions:

• using a base made of low-carbon steel, serving as a magnetic yoke
• whose transverse dimension reaches at least 10 mm
• with a surface cleaned and smooth
• without the slightest air gap between the magnet and steel
• during detachment in a direction vertical to the plane
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

Please note that the working load will differ influenced by the following factors, in order of importance:

• Gap (betwixt the magnet and the plate), because even a very small clearance (e.g. 0.5 mm) results in a drastic drop in lifting capacity by up to 50% (this also applies to varnish, corrosion or dirt).
• Loading method – catalog parameter refers to detachment vertically. When attempting to slide, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Material type – the best choice is high-permeability steel. Hardened steels may have worse magnetic properties.
• Surface structure – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Thermal conditions – NdFeB sinters have a sensitivity to temperature. At higher temperatures they lose power, and in frost gain strength (up to a certain limit).

* Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under parallel forces the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet’s surface and the plate lowers the holding force.