BM 380x180x70 [4x M8] - magnetic beam

Advantages and disadvantages of NdFeB magnets.

Besides their immense strength, neodymium magnets offer the following advantages:

• They retain attractive force for almost 10 years – the loss is just ~1% (in theory),
• They feature excellent resistance to weakening of magnetic properties due to external magnetic sources,
• By covering with a lustrous layer of gold, the element presents an proper look,
• Magnetic induction on the working layer of the magnet remains very high,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Considering the option of accurate forming and adaptation to specialized requirements, neodymium magnets can be created in a wide range of forms and dimensions, which amplifies use scope,
• Huge importance in high-tech industry – they serve a role in data components, electric motors, medical equipment, and industrial machines.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Disadvantages of NdFeB magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• 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 suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• We recommend cover - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complicated forms.
• Potential hazard resulting from small fragments of magnets pose a threat, in case of ingestion, which becomes key in the context of child health protection. It is also worth noting that small elements of these products can complicate diagnosis medical after entering the body.
• Due to complex production process, their price is higher than average,

Maximum holding power of the magnet – what it depends on?

The specified lifting capacity represents the limit force, measured under ideal test conditions, meaning:

• with the contact of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a thickness of minimum 10 mm to avoid saturation
• with an ground touching surface
• with direct contact (without paint)
• during pulling in a direction perpendicular to the plane
• in temp. approx. 20°C

Determinants of practical lifting force of a magnet

Real force impacted by working environment parameters, mainly (from most important):

• Distance (betwixt the magnet and the metal), because even a tiny clearance (e.g. 0.5 mm) results in a drastic drop in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
• Direction of force – maximum parameter is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Steel type – low-carbon steel gives the best results. Alloy admixtures decrease magnetic permeability and holding force.
• Smoothness – full contact is obtained only on smooth steel. Rough texture reduce the real contact area, weakening the magnet.
• Operating temperature – NdFeB sinters have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under a perpendicular pulling force, however under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Moreover, even a small distance {between} the magnet’s surface and the plate reduces the load capacity.