SM 19x225 [2xM6] / N50 - magnetic separator

Advantages and disadvantages of NdFeB magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• Their power remains stable, and after around 10 years it drops only by ~1% (theoretically),
• Magnets effectively defend themselves against loss of magnetization caused by ambient magnetic noise,
• In other words, due to the aesthetic surface of gold, the element looks attractive,
• They are known for high magnetic induction at the operating surface, which increases their power,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, allowing for action at temperatures approaching 230°C and above...
• Possibility of accurate forming and adjusting to defined conditions,
• Versatile presence in innovative solutions – they are commonly used in data components, brushless drives, advanced medical instruments, as well as technologically advanced constructions.
• Thanks to their power density, small magnets offer high operating force, in miniature format,

Drawbacks and weaknesses of neodymium magnets: application proposals

• At strong impacts they can crack, therefore we recommend placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets decrease their strength 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 durability even at temperatures up to 230°C
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation and corrosion.
• We suggest cover - magnetic holder, due to difficulties in creating nuts inside the magnet and complicated shapes.
• Health risk resulting from small fragments of magnets pose a threat, in case of ingestion, which becomes key in the context of child safety. It is also worth noting that small elements of these devices are able to complicate diagnosis medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which can limit application in large quantities

Maximum lifting capacity of the magnet – what contributes to it?

The force parameter is a result of laboratory testing conducted under specific, ideal conditions:

• on a block made of mild steel, perfectly concentrating the magnetic flux
• with a cross-section of at least 10 mm
• with a surface cleaned and smooth
• without the slightest air gap between the magnet and steel
• during pulling in a direction vertical to the plane
• at room temperature

Key elements affecting lifting force

During everyday use, the actual lifting capacity is determined by several key aspects, presented from crucial:

• Gap (betwixt the magnet and the plate), because even a very small clearance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to varnish, rust or debris).
• Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet exhibits significantly lower power (typically approx. 20-30% of maximum force).
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Material type – ideal substrate is high-permeability steel. Stainless steels may generate lower lifting capacity.
• Base smoothness – the smoother and more polished the plate, the better the adhesion and stronger the hold. Roughness creates an air distance.
• Thermal factor – high temperature weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity was determined using a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, whereas under shearing force the lifting capacity is smaller. Moreover, even a small distance {between} the magnet’s surface and the plate reduces the lifting capacity.