BM 550x180x70 [4x M8] - magnetic beam

Pros as well as cons of NdFeB magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (based on calculations),
• They feature excellent resistance to magnetism drop when exposed to external magnetic sources,
• A magnet with a metallic nickel surface has better aesthetics,
• They are known for high magnetic induction at the operating surface, which improves attraction properties,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Due to the ability of free shaping and adaptation to individualized requirements, neodymium magnets can be modeled in a broad palette of shapes and sizes, which expands the range of possible applications,
• Fundamental importance in electronics industry – they serve a role in data components, drive modules, diagnostic systems, and industrial machines.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a strong case, which not only secures them against impacts but also raises their durability
• Neodymium magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in producing threads and complex forms in magnets, we propose using a housing - magnetic mechanism.
• Possible danger to health – tiny shards of magnets are risky, when accidentally swallowed, which becomes key in the context of child health protection. Additionally, tiny parts of these magnets can be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Breakaway strength of the magnet in ideal conditions – what it depends on?

Breakaway force was defined for the most favorable conditions, assuming:

• on a base made of mild steel, optimally conducting the magnetic flux
• whose thickness reaches at least 10 mm
• characterized by even structure
• without the slightest air gap between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

In practice, the real power depends on a number of factors, presented from crucial:

• Gap (between the magnet and the metal), because even a very small distance (e.g. 0.5 mm) results in a drastic drop in force by up to 50% (this also applies to paint, rust or dirt).
• Angle of force application – highest force is reached only during perpendicular pulling. The shear force of the magnet along the plate is typically several times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Metal type – different alloys reacts the same. Alloy additives worsen the interaction with the magnet.
• Surface condition – smooth surfaces ensure maximum contact, which improves field saturation. Uneven metal reduce efficiency.
• Temperature – temperature increase results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under parallel forces the load capacity is reduced by as much as 5 times. Additionally, even a slight gap {between} the magnet and the plate reduces the holding force.