SM 32x200 [2xM8] / N42 - magnetic separator

Pros as well as cons of neodymium magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They do not lose strength, even over around ten years – the reduction in power is only ~1% (according to tests),
• Neodymium magnets remain exceptionally resistant to loss of magnetic properties caused by external field sources,
• A magnet with a metallic gold surface has an effective appearance,
• They show high magnetic induction at the operating surface, which increases their power,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Considering the ability of precise molding and customization to custom requirements, NdFeB magnets can be produced in a variety of forms and dimensions, which makes them more universal,
• Significant place in future technologies – they are used in data components, electromotive mechanisms, medical devices, as well as complex engineering applications.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• To avoid cracks under impact, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• NdFeB magnets lose power when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation and corrosion.
• Limited possibility of creating threads in the magnet and complex forms - preferred is cover - magnet mounting.
• Health risk related to microscopic parts of magnets pose a threat, in case of ingestion, which is particularly important in the context of child health protection. Additionally, tiny parts of these devices are able to be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Best holding force of the magnet in ideal parameters – what affects it?

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

• on a block made of structural steel, optimally conducting the magnetic flux
• possessing a massiveness of min. 10 mm to avoid saturation
• with an ground contact surface
• under conditions of ideal adhesion (metal-to-metal)
• for force applied at a right angle (pull-off, not shear)
• in temp. approx. 20°C

Determinants of practical lifting force of a magnet

Bear in mind that the application force may be lower influenced by elements below, starting with the most relevant:

• Distance – the presence of foreign body (paint, dirt, gap) interrupts the magnetic circuit, which reduces power rapidly (even by 50% at 0.5 mm).
• Direction of force – highest force is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the plate is usually many times lower (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Steel type – low-carbon steel gives the best results. Alloy steels reduce magnetic permeability and lifting capacity.
• Plate texture – ground elements guarantee perfect abutment, which increases force. Rough surfaces weaken the grip.
• Thermal factor – hot environment weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity was assessed using a polished steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, whereas under attempts to slide the magnet the holding force is lower. In addition, even a small distance {between} the magnet and the plate decreases the lifting capacity.