MP 62x42x25 / N38 - ring magnet

Advantages as well as disadvantages of neodymium magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They virtually do not lose power, because even after 10 years the performance loss is only ~1% (based on calculations),
• Magnets very well protect themselves against demagnetization caused by ambient magnetic noise,
• In other words, due to the shiny surface of gold, the element becomes visually attractive,
• Magnets are distinguished by impressive magnetic induction on the working surface,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures reaching 230°C and above...
• Thanks to flexibility in designing and the ability to adapt to unusual requirements,
• Significant place in modern industrial fields – they are used in magnetic memories, electric drive systems, advanced medical instruments, and industrial machines.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Cons of neodymium magnets: application proposals

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (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 those in rubber or plastics, which prevent oxidation as well as corrosion.
• Due to limitations in realizing nuts and complicated forms in magnets, we propose using a housing - magnetic mount.
• Possible danger 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 can complicate diagnosis medical when they are in the body.
• Due to neodymium price, their price is relatively high,

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

The declared magnet strength refers to the peak performance, obtained under laboratory conditions, specifically:

• with the contact of a sheet made of special test steel, guaranteeing full magnetic saturation
• possessing a thickness of at least 10 mm to avoid saturation
• with a plane free of scratches
• without any clearance between the magnet and steel
• under perpendicular application of breakaway force (90-degree angle)
• in neutral thermal conditions

Determinants of lifting force in real conditions

Effective lifting capacity is influenced by working environment parameters, including (from most important):

• Gap between surfaces – even a fraction of a millimeter of distance (caused e.g. by varnish or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
• Force direction – declared lifting capacity refers to pulling vertically. When attempting to slide, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• 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 lower magnetic properties and lifting capacity.
• Surface condition – smooth surfaces ensure maximum contact, which increases field saturation. Uneven metal weaken the grip.
• Temperature influence – hot environment weakens magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under shearing force the holding force is lower. Moreover, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.