MP 62x42x25 / N38 - ring magnet

Strengths as well as weaknesses of rare earth magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They virtually do not lose strength, because even after ten years the performance loss is only ~1% (based on calculations),
• They are extremely resistant to demagnetization induced by external field influence,
• Thanks to the shimmering finish, the surface of nickel, gold-plated, or silver gives an visually attractive appearance,
• They are known for high magnetic induction at the operating surface, which increases their power,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Possibility of custom shaping and adjusting to individual applications,
• Versatile presence in advanced technology sectors – they are utilized in magnetic memories, brushless drives, diagnostic systems, as well as technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which allows their use in compact constructions

Disadvantages of NdFeB magnets:

• To avoid cracks under impact, we recommend using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets experience a drop in strength. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in creating threads and complex shapes in magnets, we propose using casing - magnetic holder.
• Possible danger related to microscopic parts of magnets are risky, in case of ingestion, which gains importance in the context of child health protection. Furthermore, tiny parts of these products are able to be problematic in diagnostics medical in case of swallowing.
• With mass production the cost of neodymium magnets can be a barrier,

Best holding force of the magnet in ideal parameters – what it depends on?

The lifting capacity listed is a measurement result conducted under standard conditions:

• with the contact of a sheet made of low-carbon steel, guaranteeing maximum field concentration
• whose thickness is min. 10 mm
• with a surface free of scratches
• under conditions of gap-free contact (metal-to-metal)
• under vertical force direction (90-degree angle)
• at standard ambient temperature

What influences lifting capacity in practice

Effective lifting capacity is influenced by specific conditions, mainly (from priority):

• Air gap (betwixt the magnet and the plate), as even a microscopic distance (e.g. 0.5 mm) results in a reduction in lifting capacity by up to 50% (this also applies to varnish, rust or debris).
• Angle of force application – highest force is available only during perpendicular pulling. The shear force of the magnet along the surface is typically several times smaller (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Material composition – not every steel attracts identically. Alloy additives weaken the attraction effect.
• Smoothness – full contact is obtained only on polished steel. Rough texture reduce the real contact area, weakening the magnet.
• Thermal environment – temperature increase causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under perpendicular forces, whereas under shearing force the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet’s surface and the plate reduces the lifting capacity.