SM 32x100 [2xM8] / N42 - magnetic separator

Strengths as well as weaknesses of rare earth magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (in laboratory conditions),
• They feature excellent resistance to magnetic field loss when exposed to external fields,
• In other words, due to the smooth surface of silver, the element becomes visually attractive,
• They show high magnetic induction at the operating surface, which affects their effectiveness,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling functioning at temperatures approaching 230°C and above...
• Possibility of individual forming as well as adjusting to concrete conditions,
• Significant place in innovative solutions – they are commonly used in data components, electric drive systems, advanced medical instruments, and other advanced devices.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

What to avoid - cons of neodymium magnets and proposals for their use:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• 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 durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Limited possibility of making nuts in the magnet and complex shapes - preferred is cover - magnetic holder.
• Health risk resulting from small fragments of magnets pose a threat, in case of ingestion, which is particularly important in the context of child health protection. It is also worth noting that small elements of these products are able to complicate diagnosis medical after entering the body.
• With large orders the cost of neodymium magnets is economically unviable,

Breakaway strength of the magnet in ideal conditions – what contributes to it?

The specified lifting capacity refers to the limit force, recorded under laboratory conditions, specifically:

• on a plate made of structural steel, perfectly concentrating the magnetic flux
• possessing a thickness of min. 10 mm to ensure full flux closure
• with an ideally smooth contact surface
• without the slightest insulating layer between the magnet and steel
• during detachment in a direction perpendicular to the plane
• at standard ambient temperature

Determinants of practical lifting force of a magnet

Holding efficiency impacted by specific conditions, such as (from priority):

• Air gap (betwixt the magnet and the plate), because even a microscopic distance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to varnish, rust or debris).
• Angle of force application – highest force is obtained only during perpendicular pulling. The force required to slide of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – insufficiently thick sheet causes magnetic saturation, causing part of the flux to be lost into the air.
• Material composition – different alloys reacts the same. Alloy additives worsen the interaction with the magnet.
• Smoothness – ideal contact is obtained only on polished steel. Rough texture create air cushions, reducing force.
• Thermal factor – high temperature weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity was assessed with the use of a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet and the plate reduces the load capacity.