SM 25x175 [2xM8] / N52 - magnetic separator

Strengths as well as weaknesses of NdFeB magnets.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They have stable power, and over around 10 years their performance decreases symbolically – ~1% (in testing),
• They feature excellent resistance to magnetism drop when exposed to external magnetic sources,
• In other words, due to the aesthetic surface of gold, the element gains a professional look,
• Magnets are distinguished by maximum magnetic induction on the active area,
• 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 exact shaping as well as modifying to individual conditions,
• Universal use in modern technologies – they find application in data components, electric drive systems, advanced medical instruments, also other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which makes them useful in small systems

What to avoid - cons of neodymium magnets: application proposals

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a strong case, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets suffer a drop in power. 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, in case of application outdoors
• Due to limitations in producing threads and complicated shapes in magnets, we propose using casing - magnetic mount.
• Health risk to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the context of child health protection. Furthermore, small components of these devices are able to complicate diagnosis medical in case of swallowing.
• With large orders the cost of neodymium magnets is a challenge,

Maximum magnetic pulling force – what it depends on?

Holding force of 0 kg is a result of laboratory testing executed under standard conditions:

• using a sheet made of high-permeability steel, serving as a ideal flux conductor
• whose transverse dimension equals approx. 10 mm
• with an ideally smooth touching surface
• with total lack of distance (without paint)
• under vertical force direction (90-degree angle)
• in neutral thermal conditions

Lifting capacity in practice – influencing factors

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

• Gap between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by varnish or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Force direction – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of converting into lifting capacity.
• Steel type – mild steel gives the best results. Alloy admixtures reduce magnetic permeability and lifting capacity.
• Smoothness – ideal contact is obtained only on smooth steel. Rough texture create air cushions, reducing force.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was assessed by applying a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, however under shearing force the holding force is lower. In addition, even a minimal clearance {between} the magnet’s surface and the plate lowers the load capacity.