SM 32x250 [2xM8] / N42 - magnetic separator

Strengths as well as weaknesses of rare earth magnets.

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

• They do not lose power, even during around 10 years – the drop in power is only ~1% (based on measurements),
• They maintain their magnetic properties even under external field action,
• By covering with a reflective coating of silver, the element presents an aesthetic look,
• Magnetic induction on the top side of the magnet turns out to be maximum,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• Thanks to the potential of precise forming and customization to custom requirements, magnetic components can be manufactured in a wide range of shapes and sizes, which makes them more universal,
• Fundamental importance in electronics industry – they are commonly used in HDD drives, brushless drives, medical devices, as well as other advanced devices.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Disadvantages of neodymium magnets:

• At strong impacts they can crack, therefore we advise placing them in strong housings. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• They oxidize in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing nuts and complex forms in magnets, we propose using cover - magnetic holder.
• Potential hazard resulting from small fragments of magnets are risky, if swallowed, which becomes key in the context of child safety. It is also worth noting that small components of these products are able to disrupt the diagnostic process medical when they are in the body.
• With large orders the cost of neodymium magnets is economically unviable,

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

Breakaway force is the result of a measurement for the most favorable conditions, taking into account:

• on a block made of structural steel, optimally conducting the magnetic field
• with a cross-section no less than 10 mm
• characterized by smoothness
• with zero gap (without impurities)
• during pulling in a direction vertical to the plane
• in stable room temperature

Practical lifting capacity: influencing factors

Holding efficiency is influenced by working environment parameters, mainly (from priority):

• Distance – the presence of any layer (paint, tape, air) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to detachment vertically. When slipping, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of generating force.
• Steel grade – the best choice is high-permeability steel. Hardened steels may have worse magnetic properties.
• Surface finish – full contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Temperature – temperature increase results in weakening of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was performed on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, however under shearing force the lifting capacity is smaller. In addition, even a slight gap {between} the magnet and the plate decreases the load capacity.