SM 32x500 [2xM8] / N52 - magnetic separator

Strengths as well as weaknesses of rare earth magnets.

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

• They retain attractive force for almost 10 years – the drop is just ~1% (according to analyses),
• They possess excellent resistance to weakening of magnetic properties due to external magnetic sources,
• In other words, due to the glossy surface of nickel, the element is aesthetically pleasing,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Thanks to the option of accurate forming and customization to specialized projects, neodymium magnets can be produced in a broad palette of shapes and sizes, which makes them more universal,
• Wide application in modern industrial fields – they find application in computer drives, electric drive systems, diagnostic systems, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which allows their use in compact constructions

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only protects the magnet but also increases its resistance to damage
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend cover - magnetic mount, due to difficulties in creating nuts inside the magnet and complex shapes.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Additionally, small components of these magnets can be problematic in diagnostics medical in case of swallowing.
• With large orders the cost of neodymium magnets is a challenge,

Maximum lifting capacity of the magnet – what contributes to it?

The declared magnet strength represents the limit force, measured under laboratory conditions, specifically:

• with the contact of a yoke made of special test steel, ensuring full magnetic saturation
• whose thickness reaches at least 10 mm
• characterized by lack of roughness
• without any clearance between the magnet and steel
• under axial force direction (90-degree angle)
• at temperature approx. 20 degrees Celsius

Key elements affecting lifting force

Please note that the working load may be lower influenced by elements below, starting with the most relevant:

• Space between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Base massiveness – too thin plate causes magnetic saturation, causing part of the power to be lost to the other side.
• Steel grade – the best choice is high-permeability steel. Cast iron may attract less.
• Base smoothness – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Temperature – heating the magnet results in weakening of force. Check the thermal limit for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under shearing force the holding force is lower. Additionally, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.