MW 10x10 / N38 - cylindrical magnet

Pros as well as cons of rare earth magnets.

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

• They do not lose strength, even after around ten years – the decrease in strength is only ~1% (according to tests),
• Neodymium magnets are extremely resistant to demagnetization caused by magnetic disturbances,
• In other words, due to the smooth finish of silver, the element is aesthetically pleasing,
• Magnets have extremely high magnetic induction on the surface,
• With the right combination of magnetic alloys, they reach significant thermal stability, enabling operation at or above 230°C (depending on the form),
• Considering the ability of flexible molding and adaptation to individualized needs, magnetic components can be manufactured in a variety of forms and dimensions, which makes them more universal,
• Huge importance in modern technologies – they are commonly used in mass storage devices, electric drive systems, advanced medical instruments, also modern systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of neodymium magnets:

• To avoid cracks under impact, we suggest using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• Neodymium magnets decrease their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• They oxidize in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We suggest a housing - magnetic mechanism, due to difficulties in producing threads inside the magnet and complicated forms.
• Potential hazard resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child health protection. Furthermore, small components of these products can be problematic in diagnostics medical in case of swallowing.
• With large orders the cost of neodymium magnets is a challenge,

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

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

• with the application of a sheet made of low-carbon steel, ensuring maximum field concentration
• with a thickness no less than 10 mm
• with a plane perfectly flat
• with direct contact (no paint)
• under vertical force direction (90-degree angle)
• at ambient temperature room level

What influences lifting capacity in practice

In practice, the actual holding force results from a number of factors, presented from most significant:

• Air gap (betwixt the magnet and the metal), since even a microscopic distance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Force direction – note that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Element thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Material type – ideal substrate is high-permeability steel. Stainless steels may have worse magnetic properties.
• Surface structure – the smoother and more polished the plate, the larger the contact zone and stronger the hold. Roughness creates an air distance.
• Temperature – heating the magnet results in weakening of induction. It is worth remembering the thermal limit for a given model.

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