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

Strengths and weaknesses of rare earth magnets.

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

• They retain full power for around ten years – the loss is just ~1% (in theory),
• Magnets effectively defend themselves against loss of magnetization caused by ambient magnetic noise,
• By covering with a decorative coating of silver, the element acquires an aesthetic look,
• Neodymium magnets generate maximum magnetic induction on a small area, which increases force concentration,
• 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 individual creating and adapting to atypical needs,
• Versatile presence in high-tech industry – they are utilized in HDD drives, electric drive systems, medical equipment, and industrial machines.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Characteristics of disadvantages of neodymium magnets and ways of using them

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets decrease their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures 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 immune to moisture, in case of application outdoors
• We recommend casing - magnetic holder, due to difficulties in realizing threads inside the magnet and complicated forms.
• Potential hazard to health – tiny shards of magnets are risky, when accidentally swallowed, which gains importance in the aspect of protecting the youngest. Additionally, small components of these devices are able to disrupt the diagnostic process medical after entering the body.
• Due to neodymium price, their price is higher than average,

Maximum lifting force for a neodymium magnet – what it depends on?

Breakaway force was defined for ideal contact conditions, taking into account:

• with the application of a yoke made of low-carbon steel, ensuring full magnetic saturation
• with a thickness of at least 10 mm
• with an ground contact surface
• without the slightest air gap between the magnet and steel
• during detachment in a direction perpendicular to the plane
• in neutral thermal conditions

Determinants of lifting force in real conditions

Please note that the magnet holding may be lower subject to the following factors, in order of importance:

• Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – highest force is available only during perpendicular pulling. The resistance to sliding of the magnet along the plate is typically many times lower (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Material type – ideal substrate is high-permeability steel. Stainless steels may have worse magnetic properties.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves force. Rough surfaces reduce efficiency.
• Heat – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and in frost gain strength (up to a certain limit).

* Lifting capacity was determined with the use of a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, in contrast under shearing force the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate lowers the load capacity.