BM 650x180x70 [4x M8] - magnetic beam

Strengths and weaknesses of neodymium magnets.

Besides their tremendous field intensity, neodymium magnets offer the following advantages:

• They do not lose magnetism, even during around ten years – the decrease in strength is only ~1% (theoretically),
• They maintain their magnetic properties even under close interference source,
• By using a smooth coating of nickel, the element gains an aesthetic look,
• Magnetic induction on the surface of the magnet remains impressive,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Due to the possibility of flexible molding and adaptation to custom requirements, magnetic components can be created in a broad palette of forms and dimensions, which amplifies use scope,
• Universal use in innovative solutions – they serve a role in HDD drives, brushless drives, precision medical tools, also multitasking production systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: application proposals

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only protects the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• Due to limitations in creating threads and complicated forms in magnets, we recommend using cover - magnetic holder.
• Possible danger related to microscopic parts of magnets are risky, in case of ingestion, which gains importance in the aspect of protecting the youngest. Additionally, tiny parts of these magnets are able to complicate diagnosis medical after entering the body.
• With budget limitations the cost of neodymium magnets can be a barrier,

Detachment force of the magnet in optimal conditions – what affects it?

Magnet power is the result of a measurement for ideal contact conditions, including:

• with the contact of a yoke made of special test steel, guaranteeing full magnetic saturation
• whose thickness is min. 10 mm
• with a surface free of scratches
• without any insulating layer between the magnet and steel
• during pulling in a direction vertical to the plane
• at conditions approx. 20°C

Lifting capacity in real conditions – factors

Effective lifting capacity is influenced by specific conditions, such as (from most important):

• Distance – existence of foreign body (rust, dirt, air) interrupts the magnetic circuit, which lowers power rapidly (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet exhibits much less (typically approx. 20-30% of nominal force).
• Steel thickness – insufficiently thick steel causes magnetic saturation, causing part of the flux to be escaped to the other side.
• Metal type – different alloys reacts the same. Alloy additives weaken the attraction effect.
• Base smoothness – the more even the plate, the better the adhesion and stronger the hold. Roughness acts like micro-gaps.
• Thermal environment – heating the magnet results in weakening of induction. It is worth remembering the thermal limit for a given model.

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