SM 18x125 [2xM5] / N42 - magnetic separator

Strengths as well as weaknesses of neodymium magnets.

Besides their tremendous strength, neodymium magnets offer the following advantages:

• They retain attractive force for nearly ten years – the loss is just ~1% (based on simulations),
• Magnets very well protect themselves against loss of magnetization caused by ambient magnetic noise,
• The use of an aesthetic finish of noble metals (nickel, gold, silver) causes the element to look better,
• Magnetic induction on the surface of the magnet is extremely intense,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Possibility of custom creating and adapting to specific needs,
• Significant place in electronics industry – they are used in data components, drive modules, advanced medical instruments, as well as modern systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which allows their use in miniature devices

Cons of neodymium magnets: tips and applications.

• 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.
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, in case of application outdoors
• We suggest cover - magnetic mechanism, due to difficulties in creating threads inside the magnet and complex forms.
• Health risk to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small components of these devices are able to disrupt the diagnostic process medical in case of swallowing.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Maximum magnetic pulling force – what contributes to it?

The declared magnet strength represents the maximum value, measured under ideal test conditions, meaning:

• using a base made of low-carbon steel, functioning as a ideal flux conductor
• whose transverse dimension is min. 10 mm
• with an polished touching surface
• without any clearance between the magnet and steel
• during detachment in a direction perpendicular to the plane
• at room temperature

Practical aspects of lifting capacity – factors

Please note that the application force may be lower depending on elements below, starting with the most relevant:

• Distance (betwixt the magnet and the metal), as even a very small clearance (e.g. 0.5 mm) leads to a reduction in lifting capacity by up to 50% (this also applies to varnish, rust or dirt).
• Direction of force – highest force is reached only during perpendicular pulling. The resistance to sliding of the magnet along the surface is typically several times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of generating force.
• Plate material – mild steel gives the best results. Alloy steels decrease magnetic properties and holding force.
• Surface condition – smooth surfaces guarantee perfect abutment, which increases field saturation. Rough surfaces reduce efficiency.
• Temperature – heating the magnet results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was determined by applying a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under shearing force the lifting capacity is smaller. In addition, even a slight gap {between} the magnet and the plate decreases the holding force.