BM 750x180x70 [4x M8] - magnetic beam

Strengths as well as weaknesses of NdFeB magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They do not lose magnetism, even during approximately 10 years – the decrease in lifting capacity is only ~1% (based on measurements),
• They feature excellent resistance to magnetic field loss due to opposing magnetic fields,
• The use of an refined coating of noble metals (nickel, gold, silver) causes the element to present itself better,
• Magnets have maximum magnetic induction on the outer side,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling functioning at temperatures reaching 230°C and above...
• Thanks to the possibility of precise molding and adaptation to specialized needs, NdFeB magnets can be modeled in a wide range of shapes and sizes, which increases their versatility,
• Key role in electronics industry – they serve a role in hard drives, electromotive mechanisms, advanced medical instruments, and industrial machines.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Cons of neodymium magnets: weaknesses and usage proposals

• They are prone to damage 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 improves its resistance to damage
• 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.
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we advise using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited possibility of producing nuts in the magnet and complex shapes - recommended is cover - magnet mounting.
• Health risk to health – tiny shards of magnets pose a threat, in case of ingestion, which becomes key in the context of child health protection. Additionally, tiny parts of these devices are able to be problematic in diagnostics medical after entering the body.
• Due to complex production process, their price is relatively high,

Maximum magnetic pulling force – what affects it?

Breakaway force was determined for the most favorable conditions, including:

• on a block made of mild steel, effectively closing the magnetic field
• with a cross-section minimum 10 mm
• characterized by even structure
• without any clearance between the magnet and steel
• during pulling in a direction vertical to the plane
• at temperature room level

Lifting capacity in real conditions – factors

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

• Clearance – existence of foreign body (paint, tape, gap) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to detachment vertically. When attempting to slide, the magnet exhibits much less (often approx. 20-30% of maximum force).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Steel grade – ideal substrate is high-permeability steel. Stainless steels may generate lower lifting capacity.
• Plate texture – ground elements ensure maximum contact, which improves field saturation. Rough surfaces reduce efficiency.
• Thermal factor – high temperature weakens pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity was assessed with the use of a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, however under shearing force the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.