SMZR 32x200 / N52 - magnetic separator with handle

Pros as well as cons of rare earth magnets.

Besides their immense pulling force, neodymium magnets offer the following advantages:

• They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (in laboratory conditions),
• They are resistant to demagnetization induced by external magnetic fields,
• In other words, due to the shiny finish of nickel, the element looks attractive,
• Magnetic induction on the working layer of the magnet is maximum,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Possibility of detailed modeling as well as adjusting to concrete applications,
• Wide application in innovative solutions – they are used in mass storage devices, motor assemblies, precision medical tools, and modern systems.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Drawbacks and weaknesses of neodymium magnets: application proposals

• At strong impacts they can crack, therefore we advise placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
• NdFeB magnets demagnetize 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 extremely resistant to heat
• They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We recommend cover - magnetic holder, due to difficulties in realizing threads inside the magnet and complex forms.
• Health risk resulting from small fragments of magnets are risky, if swallowed, which gains importance in the context of child safety. It is also worth noting that small elements of these products are able to complicate diagnosis medical when they are in the body.
• With mass production the cost of neodymium magnets can be a barrier,

Maximum lifting capacity of the magnet – what affects it?

The lifting capacity listed is a result of laboratory testing executed under standard conditions:

• with the contact of a sheet made of special test steel, guaranteeing full magnetic saturation
• whose thickness equals approx. 10 mm
• with an ideally smooth touching surface
• with total lack of distance (no impurities)
• during pulling in a direction perpendicular to the mounting surface
• at conditions approx. 20°C

Practical aspects of lifting capacity – factors

In practice, the actual holding force results from several key aspects, presented from crucial:

• Gap (betwixt the magnet and the plate), since even a tiny clearance (e.g. 0.5 mm) can cause a drastic drop in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Metal type – different alloys reacts the same. High carbon content worsen the interaction with the magnet.
• Base smoothness – the more even the plate, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Temperature influence – high temperature weakens magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was conducted on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, whereas under shearing force the load capacity is reduced by as much as 75%. Moreover, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.