AM lina fi 10 mm - magnetic accessories

Pros as well as cons of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They virtually do not lose power, because even after ten years the performance loss is only ~1% (based on calculations),
• They show high resistance to demagnetization induced by presence of other magnetic fields,
• The use of an metallic coating of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Neodymium magnets create maximum magnetic induction on a their surface, which increases force concentration,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Thanks to freedom in designing and the capacity to modify to complex applications,
• Fundamental importance in advanced technology sectors – they are utilized in HDD drives, drive modules, medical devices, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which enables their usage in small systems

Characteristics of disadvantages of neodymium magnets and proposals for their use:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a special holder, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• We suggest casing - magnetic mount, due to difficulties in realizing threads inside the magnet and complicated forms.
• Health risk related to microscopic parts of magnets can be dangerous, in case of ingestion, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small elements of these magnets can be problematic in diagnostics medical in case of swallowing.
• Due to neodymium price, their price is relatively high,

Maximum magnetic pulling force – what affects it?

The force parameter is a measurement result executed under standard conditions:

• with the contact of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• with a cross-section minimum 10 mm
• characterized by even structure
• with zero gap (no paint)
• during pulling in a direction vertical to the plane
• at temperature room level

Magnet lifting force in use – key factors

Effective lifting capacity impacted by working environment parameters, mainly (from priority):

• Gap (betwixt the magnet and the plate), since even a very small clearance (e.g. 0.5 mm) results in a reduction in force by up to 50% (this also applies to varnish, corrosion or dirt).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Plate material – mild steel gives the best results. Alloy admixtures lower magnetic properties and lifting capacity.
• Base smoothness – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Temperature – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity was determined by applying a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, in contrast under shearing force the lifting capacity is smaller. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the load capacity.