SM 32x350 [2xM8] / N52 - magnetic separator

Advantages and disadvantages of neodymium magnets.

Besides their exceptional magnetic power, neodymium magnets offer the following advantages:

• Their power is durable, and after approximately 10 years it decreases only by ~1% (according to research),
• They maintain their magnetic properties even under close interference source,
• Thanks to the shiny finish, the surface of nickel, gold-plated, or silver gives an elegant appearance,
• The surface of neodymium magnets generates a unique magnetic field – this is one of their assets,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to the ability of precise forming and customization to specialized projects, neodymium magnets can be modeled in a broad palette of geometric configurations, which expands the range of possible applications,
• Universal use in advanced technology sectors – they are utilized in magnetic memories, electric motors, medical equipment, and other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which allows their use in small systems

Problematic aspects of neodymium magnets: application proposals

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets lose 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 stability even at temperatures 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 mechanism, due to difficulties in realizing nuts inside the magnet and complex forms.
• Possible danger related to microscopic parts of magnets are risky, if swallowed, which is particularly important in the context of child health protection. Additionally, small components of these devices can be problematic in diagnostics medical when they are in the body.
• With budget limitations the cost of neodymium magnets is a challenge,

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

The lifting capacity listed is a measurement result executed under specific, ideal conditions:

• with the use of a yoke made of special test steel, ensuring full magnetic saturation
• with a thickness no less than 10 mm
• with a plane free of scratches
• under conditions of gap-free contact (metal-to-metal)
• during pulling in a direction vertical to the plane
• at temperature approx. 20 degrees Celsius

Lifting capacity in practice – influencing factors

In practice, the real power is determined by many variables, ranked from most significant:

• Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – highest force is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the plate is usually several times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Steel grade – ideal substrate is pure iron steel. Hardened steels may attract less.
• Smoothness – full contact is possible only on polished steel. Rough texture reduce the real contact area, reducing force.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and in frost gain strength (up to a certain limit).

* Lifting capacity was assessed with the use of a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, in contrast under parallel forces the load capacity is reduced by as much as fivefold. Moreover, even a minimal clearance {between} the magnet’s surface and the plate lowers the load capacity.