HH 20x7.2 [M4] / N38 - through hole magnetic holder

Pros and cons of NdFeB magnets.

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

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• Neodymium magnets are characterized by remarkably resistant to demagnetization caused by external interference,
• The use of an refined layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Magnets exhibit impressive magnetic induction on the active area,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of individual shaping and optimizing to specific applications,
• Fundamental importance in future technologies – they find application in magnetic memories, brushless drives, medical equipment, also multitasking production systems.
• Compactness – despite small sizes they generate large force, 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 special housings. Such protection not only protects 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 advise our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture, in case of application outdoors
• We recommend cover - magnetic holder, due to difficulties in producing threads inside the magnet and complex shapes.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which gains importance in the context of child health protection. It is also worth noting that tiny parts of these magnets can be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum lifting force for a neodymium magnet – what contributes to it?

The declared magnet strength refers to the peak performance, recorded under laboratory conditions, specifically:

• on a block made of structural steel, perfectly concentrating the magnetic field
• possessing a thickness of at least 10 mm to avoid saturation
• characterized by even structure
• with zero gap (no coatings)
• during pulling in a direction perpendicular to the mounting surface
• in neutral thermal conditions

Practical lifting capacity: influencing factors

Real force is affected by working environment parameters, including (from priority):

• Gap (between the magnet and the metal), because even a tiny distance (e.g. 0.5 mm) leads to a decrease in force by up to 50% (this also applies to paint, rust or debris).
• Angle of force application – highest force is obtained only during pulling at a 90° angle. The force required to slide of the magnet along the plate is standardly many times lower (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin steel does not accept the full field, causing part of the power to be escaped to the other side.
• Material composition – different alloys attracts identically. Alloy additives worsen the attraction effect.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Rough surfaces reduce efficiency.
• Temperature – temperature increase causes a temporary drop of induction. Check the thermal limit for a given model.

* Lifting capacity was measured with the use of a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under shearing force the load capacity is reduced by as much as fivefold. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.