UMS 20x8.6x4.5x7 / N38 - conical magnetic holder

Pros and cons of NdFeB magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• They do not lose magnetism, even over nearly 10 years – the decrease in strength is only ~1% (theoretically),
• They feature excellent resistance to magnetic field loss as a result of external magnetic sources,
• A magnet with a metallic nickel surface has an effective appearance,
• The surface of neodymium magnets generates a powerful magnetic field – this is a distinguishing feature,
• 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...
• Thanks to modularity in constructing and the ability to adapt to specific needs,
• Versatile presence in high-tech industry – they are utilized in HDD drives, electric motors, diagnostic systems, and industrial machines.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons of neodymium magnets: tips and applications.

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets lose their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• Limited ability of creating threads in the magnet and complicated forms - preferred is casing - mounting mechanism.
• Possible danger related to microscopic parts of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child safety. Furthermore, small elements of these devices are able to be problematic in diagnostics medical when they are in the body.
• Due to complex production process, their price exceeds standard values,

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

The declared magnet strength concerns the peak performance, recorded under ideal test conditions, meaning:

• using a plate made of mild steel, serving as a circuit closing element
• with a cross-section no less than 10 mm
• with an ideally smooth contact surface
• under conditions of ideal adhesion (metal-to-metal)
• during pulling in a direction vertical to the plane
• at temperature approx. 20 degrees Celsius

Impact of factors on magnetic holding capacity in practice

Effective lifting capacity is affected by specific conditions, mainly (from priority):

• Distance – existence of any layer (paint, tape, air) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 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 nominal value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Metal type – not every steel attracts identically. High carbon content worsen the attraction effect.
• Surface finish – ideal contact is obtained only on polished steel. Rough texture create air cushions, reducing force.
• Heat – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

* Holding force was tested on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under attempts to slide the magnet the holding force is lower. Additionally, even a small distance {between} the magnet’s surface and the plate lowers the load capacity.