SM 25x275 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of neodymium magnets.

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

• They retain full power for nearly ten years – the loss is just ~1% (based on simulations),
• They maintain their magnetic properties even under close interference source,
• The use of an metallic finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• The surface of neodymium magnets generates a strong magnetic field – this is a distinguishing feature,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of individual creating and adapting to concrete conditions,
• Huge importance in innovative solutions – they serve a role in data components, motor assemblies, diagnostic systems, as well as other advanced devices.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
• Neodymium magnets decrease their force 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 stability even at temperatures up to 230°C
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation and corrosion.
• Due to limitations in producing nuts and complicated forms in magnets, we recommend using casing - magnetic mount.
• Health risk to health – tiny shards of magnets pose a threat, if swallowed, which becomes key in the context of child safety. It is also worth noting that tiny parts of these magnets can be problematic in diagnostics medical in case of swallowing.
• Due to complex production process, their price is relatively high,

Maximum lifting force for a neodymium magnet – what it depends on?

The force parameter is a theoretical maximum value conducted under specific, ideal conditions:

• on a base made of structural steel, effectively closing the magnetic field
• possessing a thickness of at least 10 mm to avoid saturation
• with a plane free of scratches
• without the slightest air gap between the magnet and steel
• during pulling in a direction vertical to the plane
• in temp. approx. 20°C

Determinants of practical lifting force of a magnet

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

• Clearance – existence of any layer (rust, dirt, gap) acts as an insulator, which reduces power rapidly (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet holds 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 passes through the material instead of converting into lifting capacity.
• Steel type – mild steel attracts best. Higher carbon content lower magnetic properties and lifting capacity.
• Surface condition – ground elements guarantee perfect abutment, which improves field saturation. Rough surfaces reduce efficiency.
• Temperature influence – high temperature reduces magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was determined using a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under shearing force the holding force is lower. Additionally, even a minimal clearance {between} the magnet and the plate decreases the holding force.