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

Pros as well as cons of rare earth magnets.

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

• They have stable power, and over nearly 10 years their attraction force decreases symbolically – ~1% (in testing),
• They retain their magnetic properties even under strong external field,
• By using a shiny coating of nickel, the element has an nice look,
• The surface of neodymium magnets generates a unique magnetic field – this is a distinguishing feature,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, allowing for functioning at temperatures reaching 230°C and above...
• Thanks to freedom in forming and the ability to customize to unusual requirements,
• Significant place in modern technologies – they serve a role in HDD drives, drive modules, advanced medical instruments, also other advanced devices.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Problematic aspects of neodymium magnets: tips and applications.

• They are fragile upon heavy impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets suffer a drop in strength. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we advise using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing threads and complex forms in magnets, we propose using casing - magnetic mechanism.
• Potential hazard resulting from small fragments of magnets are risky, in case of ingestion, which becomes key in the context of child safety. It is also worth noting that tiny parts of these products are able to complicate diagnosis medical when they are in the body.
• With budget limitations the cost of neodymium magnets is a challenge,

Maximum magnetic pulling force – what contributes to it?

The specified lifting capacity represents the peak performance, recorded under laboratory conditions, meaning:

• using a plate made of high-permeability steel, functioning as a ideal flux conductor
• with a cross-section no less than 10 mm
• with a plane perfectly flat
• without the slightest air gap between the magnet and steel
• under perpendicular application of breakaway force (90-degree angle)
• at ambient temperature room level

Impact of factors on magnetic holding capacity in practice

In practice, the actual holding force results from a number of factors, ranked from most significant:

• Space between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or dirt) diminishes the pulling force, often by half at just 0.5 mm.
• Force direction – remember that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of converting into lifting capacity.
• Plate material – mild steel gives the best results. Alloy admixtures reduce magnetic permeability and lifting capacity.
• Surface structure – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Roughness creates an air distance.
• Thermal factor – hot environment weakens magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under perpendicular forces, however under parallel forces the lifting capacity is smaller. In addition, even a small distance {between} the magnet and the plate decreases the lifting capacity.