SM 32x150 [2xM8] / N42 - magnetic separator

Strengths as well as weaknesses of rare earth magnets.

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

• Their strength remains stable, and after around ten years it drops only by ~1% (theoretically),
• They retain their magnetic properties even under close interference source,
• Thanks to the smooth finish, the coating of nickel, gold-plated, or silver gives an modern appearance,
• Magnetic induction on the surface of the magnet turns out to be extremely intense,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to flexibility in constructing and the ability to adapt to individual projects,
• Key role in innovative solutions – they are commonly used in computer drives, electromotive mechanisms, diagnostic systems, as well as multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which makes them useful in compact constructions

Disadvantages of neodymium magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in creating nuts and complicated shapes in magnets, we propose using cover - magnetic mechanism.
• Possible danger related to microscopic parts of magnets are risky, if swallowed, which gains importance in the aspect of protecting the youngest. Additionally, tiny parts of these devices can disrupt the diagnostic process medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

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

The lifting capacity listed is a theoretical maximum value executed under specific, ideal conditions:

• on a base made of structural steel, effectively closing the magnetic field
• whose transverse dimension reaches at least 10 mm
• with a plane free of scratches
• with direct contact (no paint)
• under vertical force direction (90-degree angle)
• at room temperature

Key elements affecting lifting force

In practice, the actual lifting capacity results from several key aspects, listed from the most important:

• Air gap (between the magnet and the plate), as even a microscopic distance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to paint, corrosion or debris).
• Force direction – note that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of converting into lifting capacity.
• Steel type – low-carbon steel attracts best. Alloy steels reduce magnetic permeability and lifting capacity.
• Surface condition – ground elements guarantee perfect abutment, which increases force. Rough surfaces reduce efficiency.
• Temperature influence – hot environment weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity was assessed with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, however under parallel forces the holding force is lower. In addition, even a slight gap {between} the magnet and the plate decreases the holding force.