SMZR 32x125 / N52 - magnetic separator with handle

Pros as well as cons of neodymium magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (according to literature),
• Magnets effectively resist against demagnetization caused by external fields,
• By applying a reflective coating of gold, the element has an proper look,
• Neodymium magnets ensure maximum magnetic induction on a small area, which increases force concentration,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to the ability of free shaping and customization to custom projects, NdFeB magnets can be produced in a wide range of forms and dimensions, which makes them more universal,
• Fundamental importance in high-tech industry – they are utilized in computer drives, motor assemblies, medical equipment, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which makes them useful in miniature devices

Disadvantages of neodymium magnets:

• At very strong impacts they can break, therefore we advise placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• We warn that neodymium magnets can lose their strength 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 stable to moisture, when using outdoors
• We recommend casing - magnetic mechanism, due to difficulties in producing threads inside the magnet and complicated shapes.
• Possible danger related to microscopic parts of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child safety. It is also worth noting that small elements of these devices can disrupt the diagnostic process medical in case of swallowing.
• Due to complex production process, their price is higher than average,

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

The specified lifting capacity refers to the peak performance, recorded under ideal test conditions, namely:

• on a plate made of mild steel, perfectly concentrating the magnetic flux
• possessing a massiveness of minimum 10 mm to avoid saturation
• with an ground touching surface
• under conditions of no distance (metal-to-metal)
• for force acting at a right angle (in the magnet axis)
• at conditions approx. 20°C

Lifting capacity in real conditions – factors

In practice, the actual holding force is determined by several key aspects, ranked from the most important:

• Distance (betwixt the magnet and the metal), as even a very small clearance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Direction of force – maximum parameter is available only during pulling at a 90° angle. The force required to slide of the magnet along the plate is usually several times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin steel does not close the flux, causing part of the flux to be lost to the other side.
• Steel grade – ideal substrate is high-permeability steel. Hardened steels may attract less.
• Surface condition – smooth surfaces guarantee perfect abutment, which increases force. Rough surfaces weaken the grip.
• Thermal environment – temperature increase results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, in contrast under parallel forces the holding force is lower. In addition, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.