UMGGW 29x8 [M4] GW / N38 - magnetic holder rubber internal thread

Advantages and disadvantages of neodymium magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• Their power is durable, and after around 10 years it drops only by ~1% (theoretically),
• Magnets effectively defend themselves against demagnetization caused by foreign field sources,
• The use of an shiny layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Magnetic induction on the surface of the magnet turns out to be very high,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• In view of the ability of accurate shaping and customization to individualized solutions, magnetic components can be produced in a broad palette of geometric configurations, which expands the range of possible applications,
• Fundamental importance in electronics industry – they are utilized in HDD drives, drive modules, medical equipment, also other advanced devices.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only protects the magnet but also improves its resistance to damage
• Neodymium magnets decrease their force 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 stability even at temperatures up to 230°C
• They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic holder, due to difficulties in creating nuts inside the magnet and complicated shapes.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child safety. Furthermore, tiny parts of these magnets can be problematic in diagnostics medical when they are in the body.
• Due to expensive raw materials, their price is higher than average,

Magnetic strength at its maximum – what it depends on?

Information about lifting capacity is the result of a measurement for optimal configuration, taking into account:

• using a base made of high-permeability steel, serving as a circuit closing element
• with a thickness minimum 10 mm
• with a plane perfectly flat
• without the slightest clearance between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• in temp. approx. 20°C

What influences lifting capacity in practice

Real force is affected by specific conditions, including (from most important):

• Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by varnish or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Metal type – not every steel reacts the same. Alloy additives worsen the interaction with the magnet.
• Surface structure – the smoother and more polished the plate, the better the adhesion and stronger the hold. Unevenness creates an air distance.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under shearing force the load capacity is reduced by as much as 5 times. Additionally, even a minimal clearance {between} the magnet’s surface and the plate lowers the load capacity.