SM 32x350 [2xM8] / N42 - magnetic separator

Pros and cons of neodymium magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They have unchanged lifting capacity, and over around 10 years their performance decreases symbolically – ~1% (in testing),
• Magnets very well defend themselves against demagnetization caused by external fields,
• By applying a smooth coating of nickel, the element has an nice look,
• Magnetic induction on the working layer of the magnet is impressive,
• 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...
• Thanks to freedom in constructing and the capacity to customize to client solutions,
• Significant place in advanced technology sectors – they serve a role in computer drives, drive modules, advanced medical instruments, and other advanced devices.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also improves its resistance to damage
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Limited ability of making nuts in the magnet and complicated shapes - recommended is a housing - mounting mechanism.
• Possible danger to health – tiny shards of magnets can be dangerous, if swallowed, which is particularly important in the context of child health protection. Additionally, small components of these products are able to be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Detachment force of the magnet in optimal conditions – what affects it?

Magnet power was defined for optimal configuration, taking into account:

• on a block made of structural steel, perfectly concentrating the magnetic field
• with a cross-section of at least 10 mm
• with an ground touching surface
• without the slightest air gap between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• in neutral thermal conditions

What influences lifting capacity in practice

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

• Gap between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to pulling vertically. When slipping, the magnet exhibits significantly lower power (often approx. 20-30% of nominal force).
• Plate thickness – too thin plate does not close the flux, causing part of the power to be lost to the other side.
• Material type – the best choice is pure iron steel. Hardened steels may attract less.
• Smoothness – ideal contact is possible only on polished steel. Rough texture reduce the real contact area, weakening the magnet.
• Thermal environment – temperature increase results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under a perpendicular pulling force, whereas under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet’s surface and the plate decreases the load capacity.