BM 450x180x70 [4x M8] - magnetic beam

Advantages as well as disadvantages of NdFeB magnets.

In addition to their magnetic capacity, neodymium magnets provide the following advantages:

• Their strength remains stable, and after around ten years it drops only by ~1% (according to research),
• They do not lose their magnetic properties even under strong external field,
• A magnet with a shiny gold surface is more attractive,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and are able to act (depending on the shape) even at a temperature of 230°C or more...
• Thanks to flexibility in shaping and the ability to customize to unusual requirements,
• Versatile presence in high-tech industry – they find application in data components, electromotive mechanisms, diagnostic systems, and other advanced devices.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• To avoid cracks upon strong impacts, we recommend 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 recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Limited ability of making threads in the magnet and complex shapes - recommended is casing - magnetic holder.
• Health risk to health – tiny shards of magnets can be dangerous, if swallowed, which becomes key in the context of child safety. Additionally, small elements of these products are able to complicate diagnosis medical in case of swallowing.
• Due to neodymium price, their price is higher than average,

Maximum holding power of the magnet – what contributes to it?

The load parameter shown refers to the maximum value, recorded under optimal environment, namely:

• using a plate made of mild steel, serving as a ideal flux conductor
• whose transverse dimension equals approx. 10 mm
• with an polished touching surface
• with zero gap (without paint)
• under vertical force direction (90-degree angle)
• in neutral thermal conditions

What influences lifting capacity in practice

Holding efficiency impacted by specific conditions, such as (from priority):

• Clearance – the presence of foreign body (rust, dirt, gap) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to pulling vertically. When slipping, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Steel thickness – too thin plate causes magnetic saturation, causing part of the flux to be lost into the air.
• Steel type – low-carbon steel attracts best. Alloy admixtures decrease magnetic properties and holding force.
• Base smoothness – the more even the plate, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Thermal environment – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Holding force was checked on the plate surface of 20 mm thickness, when the force acted perpendicularly, whereas under shearing force the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate lowers the holding force.