UMP 65x45 [M8]x2 GW / N38 - search holder

Advantages as well as disadvantages of neodymium magnets.

Apart from their superior power, neodymium magnets have these key benefits:

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• They retain their magnetic properties even under strong external field,
• By applying a lustrous coating of nickel, the element gains an elegant look,
• Magnets are characterized by maximum magnetic induction on the working surface,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures approaching 230°C and above...
• Thanks to freedom in forming and the ability to adapt to specific needs,
• Significant place in high-tech industry – they are utilized in mass storage devices, electric drive systems, advanced medical instruments, also other advanced devices.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

What to avoid - cons of neodymium magnets: application proposals

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only protects the magnet but also increases its resistance to damage
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic mount, due to difficulties in producing threads inside the magnet and complicated forms.
• Potential hazard resulting from small fragments of magnets pose a threat, in case of ingestion, which is particularly important in the context of child safety. It is also worth noting that small elements of these magnets are able to be problematic in diagnostics medical when they are in the body.
• With mass production the cost of neodymium magnets is economically unviable,

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

Magnet power was defined for optimal configuration, including:

• on a plate made of mild steel, effectively closing the magnetic field
• whose thickness equals approx. 10 mm
• with a surface cleaned and smooth
• without the slightest insulating layer between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• at ambient temperature room level

Lifting capacity in practice – influencing factors

During everyday use, the actual lifting capacity depends on several key aspects, listed from most significant:

• Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Chemical composition of the base – mild steel gives the best results. Alloy admixtures decrease magnetic permeability and lifting capacity.
• Surface condition – ground elements ensure maximum contact, which improves force. Rough surfaces reduce efficiency.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. At higher temperatures they lose power, and in frost they can be stronger (up to a certain limit).

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, whereas under parallel forces the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate decreases the holding force.