SMZR 32x200 / N52 - magnetic separator with handle

Advantages and disadvantages of neodymium magnets.

Apart from their notable power, neodymium magnets have these key benefits:

• They retain attractive force for nearly 10 years – the loss is just ~1% (in theory),
• They are extremely resistant to demagnetization induced by external field influence,
• In other words, due to the glossy finish of nickel, the element gains visual value,
• Magnets are distinguished by huge magnetic induction on the active area,
• 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 versatility in shaping and the capacity to adapt to specific needs,
• Versatile presence in modern technologies – they serve a role in data components, brushless drives, advanced medical instruments, as well as modern systems.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• Neodymium magnets decrease their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• We recommend cover - magnetic mechanism, due to difficulties in creating threads inside the magnet and complicated forms.
• Potential hazard related to microscopic parts of magnets are risky, when accidentally swallowed, which becomes key in the context of child health protection. It is also worth noting that small components of these products can complicate diagnosis medical when they are in the body.
• With budget limitations the cost of neodymium magnets can be a barrier,

Maximum magnetic pulling force – what contributes to it?

The force parameter is a result of laboratory testing conducted under the following configuration:

• on a plate made of mild steel, effectively closing the magnetic field
• whose thickness reaches at least 10 mm
• characterized by smoothness
• under conditions of gap-free contact (metal-to-metal)
• under vertical force direction (90-degree angle)
• at conditions approx. 20°C

Determinants of practical lifting force of a magnet

Effective lifting capacity impacted by specific conditions, including (from priority):

• Space between surfaces – every millimeter of distance (caused e.g. by varnish or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Force direction – remember that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of generating force.
• Steel grade – ideal substrate is high-permeability steel. Cast iron may have worse magnetic properties.
• Surface quality – the smoother and more polished the plate, the larger the contact zone and stronger the hold. Roughness acts like micro-gaps.
• Thermal factor – high temperature weakens pulling force. Too high temperature can permanently demagnetize the magnet.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, however under attempts to slide the magnet the holding force is lower. In addition, even a minimal clearance {between} the magnet and the plate reduces the load capacity.