SMZR 32x200 / N52 - magnetic separator with handle

Pros and cons of NdFeB magnets.

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

• They have unchanged lifting capacity, and over around ten years their performance decreases symbolically – ~1% (in testing),
• Neodymium magnets are distinguished by extremely resistant to loss of magnetic properties caused by external magnetic fields,
• Thanks to the shimmering finish, the surface of nickel, gold-plated, or silver-plated gives an professional appearance,
• Magnets are characterized by very high magnetic induction on the working surface,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures reaching 230°C and above...
• Due to the option of precise molding and adaptation to unique requirements, magnetic components can be created in a variety of geometric configurations, which expands the range of possible applications,
• Wide application in high-tech industry – they serve a role in data components, electric drive systems, medical equipment, as well as complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which makes them useful in small systems

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a special holder, which not only protects them against impacts but also increases their durability
• Neodymium magnets decrease their force 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 durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited ability of creating threads in the magnet and complicated shapes - recommended is cover - magnet mounting.
• Health risk to health – tiny shards of magnets can be dangerous, if swallowed, which becomes key in the context of child safety. Furthermore, small components of these magnets are able to be problematic in diagnostics medical when they are in the body.
• With large orders the cost of neodymium magnets is economically unviable,

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

Information about lifting capacity is the result of a measurement for ideal contact conditions, including:

• on a block made of structural steel, optimally conducting the magnetic field
• whose transverse dimension equals approx. 10 mm
• with an polished touching surface
• under conditions of gap-free contact (metal-to-metal)
• during pulling in a direction perpendicular to the plane
• at room temperature

Practical lifting capacity: influencing factors

Bear in mind that the magnet holding may be lower subject to elements below, in order of importance:

• Clearance – existence of any layer (paint, dirt, gap) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Force direction – note that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Chemical composition of the base – mild steel attracts best. Alloy admixtures decrease magnetic permeability and lifting capacity.
• Base smoothness – the smoother and more polished the surface, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Thermal environment – temperature increase results in weakening of force. Check the thermal limit for a given model.

* Holding force was checked on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under parallel forces the holding force is lower. In addition, even a small distance {between} the magnet and the plate decreases the holding force.