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

Advantages and disadvantages of neodymium magnets.

Apart from their consistent power, neodymium magnets have these key benefits:

• They do not lose strength, even during nearly ten years – the drop in strength is only ~1% (based on measurements),
• They do not lose their magnetic properties even under external field action,
• By applying a reflective coating of silver, the element acquires an elegant look,
• Neodymium magnets create maximum magnetic induction on a small surface, which allows for strong attraction,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Thanks to flexibility in designing and the ability to modify to specific needs,
• Versatile presence in high-tech industry – they are utilized in hard drives, electromotive mechanisms, precision medical tools, also other advanced devices.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

What to avoid - cons of neodymium magnets: application proposals

• At strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 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 immune to moisture, when using outdoors
• We recommend cover - magnetic mount, due to difficulties in creating nuts inside the magnet and complicated forms.
• Health risk resulting from small fragments of magnets are risky, if swallowed, which is particularly important in the context of child health protection. Additionally, small elements of these products are able to disrupt the diagnostic process medical after entering the body.
• With large orders the cost of neodymium magnets is economically unviable,

Breakaway strength of the magnet in ideal conditions – what contributes to it?

Holding force of 0 kg is a theoretical maximum value performed under standard conditions:

• on a plate made of mild steel, perfectly concentrating the magnetic field
• with a thickness of at least 10 mm
• with a surface perfectly flat
• under conditions of ideal adhesion (surface-to-surface)
• during pulling in a direction vertical to the mounting surface
• at ambient temperature room level

Determinants of lifting force in real conditions

In real-world applications, the actual lifting capacity depends on a number of factors, listed from most significant:

• Gap between surfaces – every millimeter of distance (caused e.g. by veneer or dirt) diminishes the pulling force, often by half at just 0.5 mm.
• Angle of force application – highest force is available only during pulling at a 90° angle. The shear force of the magnet along the plate is typically several times smaller (approx. 1/5 of the lifting capacity).
• Base massiveness – insufficiently thick plate causes magnetic saturation, causing part of the flux to be wasted to the other side.
• Metal type – different alloys reacts the same. High carbon content weaken the attraction effect.
• Surface finish – ideal contact is possible only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Temperature influence – high temperature weakens pulling force. Too high temperature can permanently demagnetize the magnet.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under shearing force the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate decreases the holding force.