BM 750x180x70 [4x M8] - magnetic beam

Strengths and weaknesses of neodymium magnets.

Besides their immense pulling force, neodymium magnets offer the following advantages:

• They virtually do not lose power, because even after 10 years the performance loss is only ~1% (based on calculations),
• They show high resistance to demagnetization induced by external disturbances,
• By applying a decorative coating of silver, the element presents an nice look,
• Neodymium magnets create maximum magnetic induction on a small surface, which allows for strong attraction,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to versatility in constructing and the capacity to adapt to unusual requirements,
• Wide application in innovative solutions – they are used in computer drives, electromotive mechanisms, diagnostic systems, and industrial machines.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Cons of neodymium magnets and proposals for their use:

• To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• We suggest cover - magnetic mechanism, due to difficulties in producing threads inside the magnet and complicated forms.
• Potential hazard to health – tiny shards of magnets pose a threat, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. Additionally, tiny parts of these products are able to complicate diagnosis medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Highest magnetic holding force – what affects it?

Information about lifting capacity was defined for ideal contact conditions, assuming:

• on a block made of mild steel, effectively closing the magnetic field
• possessing a thickness of minimum 10 mm to ensure full flux closure
• with an polished contact surface
• without the slightest clearance between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• at standard ambient temperature

What influences lifting capacity in practice

Effective lifting capacity is influenced by working environment parameters, such as (from priority):

• Space between magnet and steel – every millimeter of distance (caused e.g. by veneer or unevenness) drastically reduces the pulling force, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to detachment vertically. When slipping, the magnet holds much less (typically approx. 20-30% of maximum force).
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Material composition – not every steel attracts identically. High carbon content worsen the attraction effect.
• Surface quality – the more even the plate, the better the adhesion and stronger the hold. Unevenness creates an air distance.
• Temperature – temperature increase results in weakening of force. Check the maximum operating temperature for a given model.

* Lifting capacity was measured with the use of a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under shearing force the load capacity is reduced by as much as fivefold. Additionally, even a slight gap {between} the magnet’s surface and the plate reduces the holding force.