SM 25x325 [2xM8] / N52 - magnetic separator

Pros and cons of neodymium magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They virtually do not lose power, because even after 10 years the decline in efficiency is only ~1% (based on calculations),
• Magnets very well resist against loss of magnetization caused by ambient magnetic noise,
• Thanks to the metallic finish, the layer of nickel, gold, or silver-plated gives an elegant appearance,
• They show high magnetic induction at the operating surface, making them more effective,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Possibility of exact shaping as well as optimizing to complex needs,
• Key role in advanced technology sectors – they are utilized in hard drives, electromotive mechanisms, precision medical tools, also modern systems.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Characteristics of disadvantages of neodymium magnets and ways of using them

• They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only shields the magnet but also improves its resistance to damage
• When exposed to high temperature, neodymium magnets suffer 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
• They oxidize in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We suggest cover - magnetic holder, due to difficulties in realizing nuts inside the magnet and complex forms.
• Health risk to health – tiny shards of magnets pose a threat, when accidentally swallowed, which gains importance in the aspect of protecting the youngest. Additionally, tiny parts of these devices can disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Magnetic strength at its maximum – what it depends on?

Information about lifting capacity is the result of a measurement for ideal contact conditions, assuming:

• with the use of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a thickness of minimum 10 mm to ensure full flux closure
• characterized by smoothness
• under conditions of no distance (surface-to-surface)
• under vertical force vector (90-degree angle)
• in neutral thermal conditions

What influences lifting capacity in practice

Please note that the application force will differ subject to the following factors, starting with the most relevant:

• Gap (between the magnet and the plate), since even a microscopic distance (e.g. 0.5 mm) results in a decrease in force by up to 50% (this also applies to paint, corrosion or dirt).
• Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Plate thickness – too thin steel does not accept the full field, causing part of the flux to be lost into the air.
• Chemical composition of the base – low-carbon steel attracts best. Alloy admixtures decrease magnetic properties and lifting capacity.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves force. Rough surfaces reduce efficiency.
• Temperature influence – high temperature reduces magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under perpendicular forces, in contrast under parallel forces the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet and the plate lowers the holding force.