SM 25x175 [2xM8] / N52 - magnetic separator

Advantages as well as disadvantages of NdFeB magnets.

In addition to their magnetic capacity, neodymium magnets provide the following advantages:

• They retain full power for around 10 years – the drop is just ~1% (according to analyses),
• They have excellent resistance to magnetic field loss when exposed to external magnetic sources,
• A magnet with a shiny silver surface is more attractive,
• The surface of neodymium magnets generates a powerful magnetic field – this is one of their assets,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for operation at temperatures approaching 230°C and above...
• Considering the potential of free shaping and customization to custom projects, neodymium magnets can be produced in a variety of shapes and sizes, which makes them more universal,
• Huge importance in innovative solutions – they serve a role in HDD drives, brushless drives, diagnostic systems, also technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which makes them useful in small systems

Disadvantages of neodymium magnets:

• At strong impacts they can break, therefore we recommend placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and 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 start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• Due to limitations in creating nuts and complex shapes in magnets, we recommend using cover - magnetic mechanism.
• Health risk resulting from small fragments of magnets are risky, if swallowed, which is particularly important in the aspect of protecting the youngest. Additionally, small elements of these devices are able to be problematic in diagnostics medical after entering the body.
• With budget limitations the cost of neodymium magnets can be a barrier,

Highest magnetic holding force – what it depends on?

The declared magnet strength represents the limit force, obtained under laboratory conditions, meaning:

• on a base made of mild steel, optimally conducting the magnetic flux
• whose transverse dimension reaches at least 10 mm
• characterized by even structure
• with direct contact (without coatings)
• for force applied at a right angle (pull-off, not shear)
• at temperature room level

Practical lifting capacity: influencing factors

Please note that the working load will differ subject to the following factors, in order of importance:

• Distance – existence of any layer (paint, dirt, air) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet exhibits much less (often approx. 20-30% of maximum force).
• Wall thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of generating force.
• Steel grade – ideal substrate is pure iron steel. Stainless steels may attract less.
• Surface finish – ideal contact is obtained only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Operating temperature – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity was measured using a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, whereas under shearing force the holding force is lower. Additionally, even a small distance {between} the magnet and the plate decreases the holding force.