SMZR 25x150 / N52 - magnetic separator with handle

Strengths and weaknesses of neodymium magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• Their power is durable, and after around 10 years it decreases only by ~1% (theoretically),
• They retain their magnetic properties even under external field action,
• In other words, due to the glossy surface of gold, the element gains a professional look,
• Neodymium magnets generate maximum magnetic induction on a their surface, which increases force concentration,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, allowing for functioning at temperatures approaching 230°C and above...
• Possibility of detailed shaping as well as adapting to concrete conditions,
• Fundamental importance in modern industrial fields – they find application in magnetic memories, electric motors, medical equipment, and other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which allows their use in compact constructions

Disadvantages of neodymium magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also improves its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in strength. 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
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation as well as corrosion.
• Due to limitations in creating nuts and complex shapes in magnets, we recommend using a housing - magnetic mechanism.
• Potential hazard related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child health protection. Furthermore, small components of these products are able to complicate diagnosis medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Optimal lifting capacity of a neodymium magnet – what it depends on?

The specified lifting capacity refers to the limit force, recorded under ideal test conditions, namely:

• with the application of a sheet made of low-carbon steel, ensuring maximum field concentration
• whose transverse dimension reaches at least 10 mm
• with a surface perfectly flat
• with total lack of distance (no coatings)
• during detachment in a direction vertical to the plane
• in temp. approx. 20°C

Magnet lifting force in use – key factors

Please note that the working load may be lower depending on the following factors, in order of importance:

• Clearance – existence of foreign body (rust, dirt, air) interrupts the magnetic circuit, which lowers power rapidly (even by 50% at 0.5 mm).
• Force direction – note that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Base massiveness – too thin sheet does not close the flux, causing part of the flux to be wasted to the other side.
• Chemical composition of the base – low-carbon steel attracts best. Alloy admixtures decrease magnetic properties and holding force.
• Smoothness – ideal contact is obtained only on smooth steel. Any scratches and bumps create air cushions, weakening the magnet.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Holding force was checked on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under attempts to slide the magnet the holding force is lower. In addition, even a slight gap {between} the magnet and the plate reduces the holding force.