MP 5x2.7/1.2x5 C / N38 - ring magnet

Advantages as well as disadvantages of rare earth magnets.

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

• They retain full power for almost ten years – the loss is just ~1% (according to analyses),
• They are resistant to demagnetization induced by external field influence,
• By applying a shiny layer of silver, the element acquires an nice look,
• They show high magnetic induction at the operating surface, which improves attraction properties,
• 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...
• Possibility of exact modeling and adapting to precise requirements,
• Wide application in advanced technology sectors – they are utilized in data components, motor assemblies, advanced medical instruments, and complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Problematic aspects of neodymium magnets: tips and applications.

• At strong impacts they can crack, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• We warn that neodymium magnets can reduce their power 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 stable to moisture, when using outdoors
• Limited ability of making nuts in the magnet and complicated forms - preferred is a housing - magnetic holder.
• Potential hazard to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child health protection. Furthermore, small components of these products are able to be problematic in diagnostics medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which can limit application in large quantities

Highest magnetic holding force – what it depends on?

The lifting capacity listed is a theoretical maximum value executed under specific, ideal conditions:

• with the contact of a sheet made of special test steel, guaranteeing full magnetic saturation
• possessing a massiveness of min. 10 mm to avoid saturation
• characterized by smoothness
• with total lack of distance (no impurities)
• during detachment in a direction perpendicular to the mounting surface
• at standard ambient temperature

What influences lifting capacity in practice

During everyday use, the real power results from several key aspects, ranked from crucial:

• Distance (between the magnet and the metal), as even a microscopic distance (e.g. 0.5 mm) leads to a reduction in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
• Force direction – declared lifting capacity refers to detachment vertically. When attempting to slide, the magnet exhibits much less (often approx. 20-30% of nominal force).
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of converting into lifting capacity.
• Material composition – not every steel reacts the same. High carbon content worsen the interaction with the magnet.
• Surface structure – the more even the surface, the better the adhesion and higher the lifting capacity. Unevenness acts like micro-gaps.
• Temperature – temperature increase results in weakening of induction. Check the thermal limit for a given model.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Moreover, even a minimal clearance {between} the magnet’s surface and the plate decreases the load capacity.