MW 8x1.5 / N38 - cylindrical magnet

Pros and cons of rare earth magnets.

Apart from their strong magnetism, neodymium magnets have these key benefits:

• They do not lose strength, even after approximately 10 years – the drop in lifting capacity is only ~1% (theoretically),
• They are noted for resistance to demagnetization induced by external field influence,
• By covering with a lustrous coating of gold, the element presents an nice look,
• Magnets are characterized by huge magnetic induction on the surface,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Considering the option of free forming and customization to specialized solutions, neodymium magnets can be created in a variety of geometric configurations, which makes them more universal,
• Wide application in modern industrial fields – they find application in hard drives, electric motors, medical devices, as well as industrial machines.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also improves its resistance to damage
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We suggest casing - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complicated forms.
• Health risk related to microscopic parts of magnets are risky, if swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small components of these magnets are able to disrupt the diagnostic process medical after entering the body.
• Due to expensive raw materials, their price is higher than average,

Maximum lifting capacity of the magnet – what it depends on?

The specified lifting capacity concerns the maximum value, recorded under optimal environment, meaning:

• on a base made of mild steel, perfectly concentrating the magnetic field
• possessing a thickness of at least 10 mm to ensure full flux closure
• characterized by smoothness
• without the slightest insulating layer between the magnet and steel
• under vertical application of breakaway force (90-degree angle)
• at room temperature

Determinants of practical lifting force of a magnet

During everyday use, the real power is determined by a number of factors, ranked from the most important:

• Air gap (betwixt the magnet and the metal), as even a very small distance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to paint, corrosion or dirt).
• Direction of force – highest force is reached only during perpendicular pulling. The resistance to sliding of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Metal type – not every steel attracts identically. High carbon content weaken the attraction effect.
• Plate texture – ground elements guarantee perfect abutment, which improves field saturation. Rough surfaces reduce efficiency.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. When it is hot they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Holding force was measured on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet and the plate lowers the load capacity.