SM 32x350 [2xM8] / N52 - magnetic separator

Strengths as well as weaknesses of NdFeB magnets.

Besides their exceptional strength, neodymium magnets offer the following advantages:

• They retain attractive force for almost ten years – the loss is just ~1% (based on simulations),
• They possess excellent resistance to magnetism drop due to opposing magnetic fields,
• By covering with a reflective layer of silver, the element gains an nice look,
• Neodymium magnets achieve maximum magnetic induction on a contact point, which allows for strong attraction,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Possibility of accurate shaping as well as adjusting to defined applications,
• Significant place in modern technologies – they are utilized in magnetic memories, motor assemblies, medical equipment, as well as modern systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of neodymium magnets:

• At very strong impacts they can crack, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets decrease their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• They rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in creating threads and complicated shapes in magnets, we propose using a housing - magnetic mount.
• Health risk to health – tiny shards of magnets can be dangerous, in case of ingestion, which is particularly important in the context of child health protection. It is also worth noting that tiny parts of these devices are able to disrupt the diagnostic process medical in case of swallowing.
• Due to complex production process, their price is relatively high,

Maximum lifting force for a neodymium magnet – what it depends on?

The specified lifting capacity refers to the maximum value, measured under ideal test conditions, specifically:

• on a base made of structural steel, perfectly concentrating the magnetic flux
• whose transverse dimension equals approx. 10 mm
• with an ideally smooth contact surface
• with direct contact (no paint)
• during detachment in a direction perpendicular to the mounting surface
• in stable room temperature

What influences lifting capacity in practice

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

• Gap between surfaces – every millimeter of separation (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Force direction – declared lifting capacity refers to pulling vertically. When slipping, the magnet holds significantly lower power (often approx. 20-30% of nominal force).
• Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Metal type – different alloys reacts the same. High carbon content worsen the attraction effect.
• Surface quality – the more even the plate, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, whereas under attempts to slide the magnet the holding force is lower. Moreover, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.