SM 25x350 [2xM8] / N52 - magnetic separator

Advantages and disadvantages of rare earth magnets.

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

• They do not lose magnetism, even during nearly ten years – the drop in strength is only ~1% (theoretically),
• Neodymium magnets are highly resistant to loss of magnetic properties caused by magnetic disturbances,
• A magnet with a metallic gold surface looks better,
• Magnetic induction on the working part of the magnet turns out to be maximum,
• 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 accurate creating and adjusting to complex applications,
• Fundamental importance in advanced technology sectors – they are used in mass storage devices, electric drive systems, diagnostic systems, also complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets decrease their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• They oxidize in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We suggest cover - magnetic holder, due to difficulties in realizing nuts inside the magnet and complicated shapes.
• Potential hazard to health – tiny shards of magnets are risky, in case of ingestion, which becomes key in the aspect of protecting the youngest. Additionally, small elements of these products are able to disrupt the diagnostic process medical after entering the body.
• With large orders the cost of neodymium magnets is economically unviable,

Maximum lifting force for a neodymium magnet – what affects it?

Magnet power was defined for ideal contact conditions, taking into account:

• using a base made of high-permeability steel, serving as a magnetic yoke
• with a cross-section minimum 10 mm
• with an polished contact surface
• with direct contact (no coatings)
• for force applied at a right angle (pull-off, not shear)
• at standard ambient temperature

Determinants of lifting force in real conditions

Please note that the magnet holding may be lower depending on the following factors, in order of importance:

• Distance – the presence of any layer (rust, dirt, gap) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Force direction – catalog parameter refers to detachment vertically. When applying parallel force, the magnet exhibits much less (often approx. 20-30% of maximum force).
• Base massiveness – too thin steel does not accept the full field, causing part of the flux to be lost into the air.
• Steel type – low-carbon steel gives the best results. Alloy admixtures reduce magnetic permeability and holding force.
• Plate texture – smooth surfaces guarantee perfect abutment, which improves field saturation. Uneven metal weaken the grip.
• Thermal conditions – NdFeB sinters have a sensitivity to temperature. At higher temperatures they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity was measured using a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under shearing force the load capacity is reduced by as much as 75%. Moreover, even a slight gap {between} the magnet and the plate reduces the load capacity.