SM 32x275 [2xM8] / N42 - magnetic separator

Advantages as well as disadvantages of neodymium magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They have stable power, and over around ten years their attraction force decreases symbolically – ~1% (in testing),
• They maintain their magnetic properties even under external field action,
• In other words, due to the glossy layer of gold, the element gains visual value,
• Magnets have maximum magnetic induction on the outer layer,
• 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 modularity in forming and the capacity to modify to individual projects,
• Key role in modern technologies – they are used in data components, brushless drives, diagnostic systems, also modern systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which allows their use in compact constructions

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a special holder, which not only protects them against impacts but also increases their durability
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in creating nuts and complex shapes in magnets, we propose using cover - magnetic mechanism.
• Health risk related to microscopic parts of magnets pose a threat, if swallowed, which gains importance in the context of child health protection. Additionally, small elements of these magnets are able to complicate diagnosis medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Detachment force of the magnet in optimal conditions – what contributes to it?

The load parameter shown refers to the peak performance, measured under laboratory conditions, specifically:

• using a plate made of low-carbon steel, serving as a ideal flux conductor
• whose thickness equals approx. 10 mm
• with a surface cleaned and smooth
• with zero gap (no paint)
• during pulling in a direction perpendicular to the plane
• at room temperature

What influences lifting capacity in practice

During everyday use, the actual holding force is determined by many variables, listed from crucial:

• Gap (between the magnet and the plate), since even a tiny distance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to varnish, rust or debris).
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Steel type – mild steel gives the best results. Higher carbon content reduce magnetic permeability and holding force.
• Surface structure – the smoother and more polished the surface, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Operating temperature – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under perpendicular forces, whereas under shearing force the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet and the plate reduces the lifting capacity.