SM 25x225 [2xM8] / N42 - magnetic separator

Pros as well as cons of rare earth magnets.

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

• They retain full power for almost ten years – the drop is just ~1% (based on simulations),
• Magnets effectively defend themselves against loss of magnetization caused by foreign field sources,
• In other words, due to the aesthetic layer of gold, the element gains visual value,
• Neodymium magnets deliver maximum magnetic induction on a small surface, which increases force concentration,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Thanks to freedom in forming and the ability to modify to client solutions,
• Wide application in electronics industry – they are utilized in mass storage devices, drive modules, advanced medical instruments, as well as industrial machines.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Drawbacks and weaknesses of neodymium magnets: weaknesses and usage proposals

• Brittleness is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a steel housing, which not only protects them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
• Due to limitations in realizing nuts and complicated forms in magnets, we propose using a housing - magnetic mount.
• Potential hazard to health – tiny shards of magnets are risky, in case of ingestion, which is particularly important in the context of child health protection. Furthermore, tiny parts of these products are able to disrupt the diagnostic process medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

The specified lifting capacity represents the maximum value, measured under laboratory conditions, meaning:

• on a plate made of structural steel, effectively closing the magnetic field
• possessing a thickness of at least 10 mm to ensure full flux closure
• characterized by even structure
• with direct contact (no coatings)
• under vertical force direction (90-degree angle)
• at ambient temperature room level

Magnet lifting force in use – key factors

In practice, the actual lifting capacity depends on many variables, listed from most significant:

• Distance – existence of any layer (paint, dirt, air) interrupts the magnetic circuit, which reduces capacity steeply (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to pulling vertically. When slipping, the magnet exhibits significantly lower power (often approx. 20-30% of maximum force).
• Base massiveness – insufficiently thick steel does not accept the full field, causing part of the power to be lost into the air.
• Metal type – not every steel attracts identically. Alloy additives worsen the interaction with the magnet.
• Surface structure – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Temperature – temperature increase causes a temporary drop of induction. Check the maximum operating temperature for a given model.

* Lifting capacity was assessed with the use of a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, however under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet and the plate lowers the holding force.