SM 32x150 [2xM8] / N42 - magnetic separator

Pros and cons of neodymium magnets.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They do not lose magnetism, even over around ten years – the drop in lifting capacity is only ~1% (theoretically),
• They have excellent resistance to magnetism drop when exposed to opposing magnetic fields,
• By applying a decorative layer of silver, the element gains an modern look,
• Magnetic induction on the surface of the magnet remains extremely intense,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of accurate modeling and adapting to complex needs,
• Huge importance in electronics industry – they find application in magnetic memories, electromotive mechanisms, advanced medical instruments, also modern systems.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which makes them useful in small systems

What to avoid - cons of neodymium magnets and ways of using them

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a strong case, which not only secures them against impacts but also raises their durability
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we suggest 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 casing - magnetic mechanism, due to difficulties in realizing threads inside the magnet and complex forms.
• Possible danger related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the context of child safety. Additionally, small elements of these devices can disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Maximum lifting capacity of the magnet – what affects it?

The specified lifting capacity concerns the peak performance, obtained under laboratory conditions, namely:

• with the use of a sheet made of special test steel, guaranteeing maximum field concentration
• possessing a thickness of minimum 10 mm to avoid saturation
• with an polished touching surface
• under conditions of ideal adhesion (metal-to-metal)
• during detachment in a direction perpendicular to the mounting surface
• at ambient temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

In real-world applications, the real power is determined by many variables, listed from crucial:

• Air gap (between the magnet and the plate), since even a tiny distance (e.g. 0.5 mm) leads to a reduction in lifting capacity by up to 50% (this also applies to paint, corrosion or dirt).
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Base massiveness – too thin plate does not close the flux, causing part of the flux to be escaped into the air.
• Metal type – not every steel attracts identically. High carbon content weaken the interaction with the magnet.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves field saturation. Rough surfaces weaken the grip.
• Temperature – heating the magnet causes a temporary drop of induction. Check the thermal limit for a given model.

* Holding force was checked on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under shearing force the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate reduces the lifting capacity.