SMZR 32x100 / N52 - magnetic separator with handle

Strengths as well as weaknesses of neodymium magnets.

Besides their exceptional field intensity, neodymium magnets offer the following advantages:

• They do not lose power, even after around ten years – the decrease in strength is only ~1% (based on measurements),
• They feature excellent resistance to weakening of magnetic properties when exposed to external magnetic sources,
• By covering with a smooth layer of nickel, the element acquires an proper look,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Due to the potential of flexible shaping and customization to custom solutions, neodymium magnets can be created in a broad palette of forms and dimensions, which increases their versatility,
• Key role in modern technologies – they are commonly used in HDD drives, drive modules, medical devices, as well as modern systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, in miniature format,

Characteristics of disadvantages of neodymium magnets: tips and applications.

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• Neodymium magnets decrease their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• They oxidize in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic mount, due to difficulties in realizing threads inside the magnet and complex shapes.
• Potential hazard resulting from small fragments of magnets pose a threat, in case of ingestion, which becomes key in the context of child safety. It is also worth noting that small components of these products can be problematic in diagnostics medical when they are in the body.
• Due to complex production process, their price is relatively high,

Best holding force of the magnet in ideal parameters – what contributes to it?

The force parameter is a theoretical maximum value conducted under standard conditions:

• using a sheet made of high-permeability steel, acting as a circuit closing element
• possessing a massiveness of min. 10 mm to avoid saturation
• with a plane cleaned and smooth
• under conditions of no distance (metal-to-metal)
• under axial force vector (90-degree angle)
• at temperature approx. 20 degrees Celsius

Determinants of practical lifting force of a magnet

Holding efficiency impacted by specific conditions, mainly (from most important):

• Clearance – the presence of any layer (paint, dirt, air) acts as an insulator, which lowers power steeply (even by 50% at 0.5 mm).
• Force direction – remember that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Steel type – low-carbon steel attracts best. Higher carbon content decrease magnetic properties and holding force.
• Surface condition – ground elements guarantee perfect abutment, which increases force. Uneven metal reduce efficiency.
• Operating temperature – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and in frost they can be stronger (up to a certain limit).

* Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under parallel forces the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet and the plate lowers the load capacity.