SM 18x275 [2xM5] / N42 - magnetic separator

Pros and cons of neodymium magnets.

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

• Their power remains stable, and after around 10 years it drops only by ~1% (theoretically),
• Magnets very well resist against loss of magnetization caused by foreign field sources,
• The use of an aesthetic layer of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• The surface of neodymium magnets generates a maximum magnetic field – this is a distinguishing feature,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Thanks to freedom in constructing and the ability to modify to individual projects,
• Universal use in modern industrial fields – they find application in computer drives, drive modules, advanced medical instruments, also industrial machines.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons of neodymium magnets: tips and applications.

• 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 reduce their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We suggest casing - magnetic mechanism, due to difficulties in producing threads inside the magnet and complex forms.
• Possible danger to health – tiny shards of magnets pose a threat, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, tiny parts of these products are able to complicate diagnosis medical in case of swallowing.
• With mass production the cost of neodymium magnets can be a barrier,

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

The force parameter is a measurement result executed under standard conditions:

• using a plate made of mild steel, serving as a circuit closing element
• possessing a thickness of at least 10 mm to ensure full flux closure
• with an polished contact surface
• without any insulating layer between the magnet and steel
• during pulling in a direction vertical to the mounting surface
• in temp. approx. 20°C

Practical lifting capacity: influencing factors

Real force impacted by working environment parameters, including (from priority):

• Clearance – the presence of foreign body (paint, dirt, gap) acts as an insulator, which lowers power rapidly (even by 50% at 0.5 mm).
• Force direction – remember that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Steel thickness – too thin steel does not close the flux, causing part of the power to be escaped to the other side.
• Material composition – different alloys reacts the same. Alloy additives worsen the interaction with the magnet.
• Smoothness – full contact is obtained only on polished steel. Rough texture reduce the real contact area, reducing force.
• Thermal environment – heating the magnet causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was measured by applying a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet and the plate reduces the lifting capacity.