SM 32x150 [2xM8] / N42 - magnetic separator

Advantages and disadvantages of neodymium magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They do not lose magnetism, even after around 10 years – the reduction in strength is only ~1% (theoretically),
• They retain their magnetic properties even under external field action,
• A magnet with a smooth nickel surface has an effective appearance,
• Neodymium magnets ensure maximum magnetic induction on a contact point, which ensures high operational effectiveness,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Thanks to freedom in designing and the ability to customize to specific needs,
• Key role in innovative solutions – they find application in data components, drive modules, medical equipment, and multitasking production systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,

What to avoid - cons of neodymium magnets: weaknesses and usage proposals

• To avoid cracks under impact, we suggest using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium magnets lose 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 stability even at temperatures 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 stable to moisture, in case of application outdoors
• We recommend cover - magnetic mount, due to difficulties in producing threads inside the magnet and complex forms.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which becomes key in the context of child health protection. Additionally, small components of these products can be problematic in diagnostics medical when they are in the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Optimal lifting capacity of a neodymium magnet – what affects it?

The specified lifting capacity concerns the peak performance, measured under ideal test conditions, specifically:

• using a base made of high-permeability steel, acting as a ideal flux conductor
• whose thickness reaches at least 10 mm
• with an polished contact surface
• with direct contact (without paint)
• for force applied at a right angle (in the magnet axis)
• in stable room temperature

Magnet lifting force in use – key factors

It is worth knowing that the working load will differ subject to the following factors, starting with the most relevant:

• Gap (between the magnet and the metal), since even a microscopic clearance (e.g. 0.5 mm) can cause a drastic drop in lifting capacity by up to 50% (this also applies to varnish, rust or debris).
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Steel thickness – insufficiently thick sheet causes magnetic saturation, causing part of the power to be lost to the other side.
• Material composition – not every steel reacts the same. Alloy additives worsen the attraction effect.
• Surface finish – ideal contact is possible only on smooth steel. Rough texture reduce the real contact area, weakening the magnet.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was assessed with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the load capacity.