SM 25x100 [2xM8] / N42 - magnetic separator

Strengths as well as weaknesses of NdFeB magnets.

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

• They do not lose magnetism, even during around ten years – the drop in strength is only ~1% (according to tests),
• Neodymium magnets prove to be remarkably resistant to magnetic field loss caused by external interference,
• By applying a shiny coating of nickel, the element presents an modern look,
• Magnetic induction on the working layer of the magnet remains 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...
• Due to the possibility of free shaping and adaptation to specialized requirements, NdFeB magnets can be modeled in a variety of geometric configurations, which amplifies use scope,
• Key role in modern industrial fields – they are utilized in data components, drive modules, medical equipment, as well as industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which makes them useful in compact constructions

What to avoid - cons of neodymium magnets: tips and applications.

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium magnets decrease their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore during using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• We recommend casing - magnetic mount, due to difficulties in producing nuts inside the magnet and complex shapes.
• Potential hazard resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, small elements of these devices are able to be problematic in diagnostics medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which can limit application in large quantities

Maximum lifting force for a neodymium magnet – what contributes to it?

Breakaway force was determined for the most favorable conditions, including:

• with the contact of a sheet made of special test steel, ensuring maximum field concentration
• possessing a thickness of minimum 10 mm to avoid saturation
• characterized by even structure
• without any air gap between the magnet and steel
• during detachment in a direction vertical to the plane
• at conditions approx. 20°C

Lifting capacity in practice – influencing factors

Real force is influenced by specific conditions, mainly (from most important):

• Distance – the presence of foreign body (rust, tape, gap) interrupts the magnetic circuit, which lowers capacity steeply (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to pulling vertically. When slipping, the magnet exhibits significantly lower power (often approx. 20-30% of maximum force).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of generating force.
• Steel grade – the best choice is pure iron steel. Hardened steels may attract less.
• Plate texture – smooth surfaces ensure maximum contact, which increases field saturation. Rough surfaces reduce efficiency.
• Thermal factor – high temperature weakens pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity was determined by applying a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, in contrast under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.