SMZR 32x125 / N52 - magnetic separator with handle

Strengths and weaknesses of NdFeB magnets.

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

• They have constant strength, and over around 10 years their attraction force decreases symbolically – ~1% (in testing),
• Neodymium magnets are characterized by exceptionally resistant to magnetic field loss caused by magnetic disturbances,
• Thanks to the shimmering finish, the layer of nickel, gold-plated, or silver gives an elegant appearance,
• The surface of neodymium magnets generates a intense magnetic field – this is a distinguishing feature,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• In view of the option of free shaping and customization to custom needs, NdFeB magnets can be produced in a broad palette of forms and dimensions, which increases their versatility,
• Versatile presence in advanced technology sectors – they serve a role in magnetic memories, electric drive systems, medical devices, also industrial machines.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Cons of neodymium magnets: application proposals

• To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can corrode. Therefore during using outdoors, we advise using waterproof magnets made of rubber, plastic or other material protecting against moisture
• We recommend cover - magnetic mechanism, due to difficulties in realizing threads inside the magnet and complex forms.
• Potential hazard related to microscopic parts of magnets pose a threat, in case of ingestion, which is particularly important in the context of child safety. Additionally, small components of these magnets can complicate diagnosis medical after entering the body.
• Due to neodymium price, their price is higher than average,

Detachment force of the magnet in optimal conditions – what affects it?

Information about lifting capacity was defined for ideal contact conditions, assuming:

• with the contact of a sheet made of special test steel, ensuring full magnetic saturation
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by smoothness
• with total lack of distance (without coatings)
• under perpendicular force direction (90-degree angle)
• at conditions approx. 20°C

Determinants of lifting force in real conditions

It is worth knowing that the application force will differ subject to the following factors, in order of importance:

• Space between surfaces – even a fraction of a millimeter of separation (caused e.g. by varnish or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is reached only during perpendicular pulling. The resistance to sliding of the magnet along the surface is standardly several times smaller (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin steel does not close the flux, causing part of the power to be escaped to the other side.
• Steel grade – the best choice is high-permeability steel. Hardened steels may have worse magnetic properties.
• Surface structure – the smoother and more polished the surface, the better the adhesion and stronger the hold. Roughness creates an air distance.
• Thermal environment – temperature increase causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was performed on plates with a smooth surface of suitable thickness, under perpendicular forces, however under parallel forces the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet and the plate reduces the holding force.