MP 30x6x10 / N38 - ring magnet

Advantages as well as disadvantages of NdFeB magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• They have constant strength, and over more than 10 years their performance decreases symbolically – ~1% (according to theory),
• They show high resistance to demagnetization induced by presence of other magnetic fields,
• By using a shiny coating of nickel, the element acquires an professional look,
• They feature high magnetic induction at the operating surface, which increases their power,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to the potential of free forming and customization to individualized projects, neodymium magnets can be produced in a wide range of geometric configurations, which amplifies use scope,
• Significant place in modern technologies – they serve a role in mass storage devices, electromotive mechanisms, medical devices, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which enables their usage in compact constructions

Characteristics of disadvantages of neodymium magnets: tips and applications.

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only shields the magnet but also improves its resistance to damage
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Due to limitations in realizing nuts and complex forms in magnets, we propose using cover - magnetic mount.
• Potential hazard to health – tiny shards of magnets can be dangerous, if swallowed, which is particularly important in the context of child health protection. It is also worth noting that small components of these products are able to complicate diagnosis medical in case of swallowing.
• Due to expensive raw materials, their price is higher than average,

Magnetic strength at its maximum – what it depends on?

Information about lifting capacity was determined for ideal contact conditions, assuming:

• on a base made of mild steel, perfectly concentrating the magnetic field
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by lack of roughness
• under conditions of ideal adhesion (metal-to-metal)
• during detachment in a direction perpendicular to the plane
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

It is worth knowing that the application force will differ influenced by the following factors, starting with the most relevant:

• Distance (between the magnet and the plate), as even a tiny distance (e.g. 0.5 mm) results in a decrease in force by up to 50% (this also applies to paint, corrosion or debris).
• Angle of force application – maximum parameter is available only during pulling at a 90° angle. The shear force of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin plate causes magnetic saturation, causing part of the flux to be escaped into the air.
• Material type – ideal substrate is high-permeability steel. Hardened steels may generate lower lifting capacity.
• Base smoothness – the smoother and more polished the surface, the better the adhesion and stronger the hold. Unevenness creates an air distance.
• Heat – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and in frost they can be stronger (up to a certain limit).

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, whereas under attempts to slide the magnet the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.