KM HF - 22 kg - magnetic bracket

Strengths as well as weaknesses of NdFeB magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• Their magnetic field is durable, and after approximately ten years it drops only by ~1% (according to research),
• They show high resistance to demagnetization induced by presence of other magnetic fields,
• A magnet with a shiny silver surface is more attractive,
• They are known for high magnetic induction at the operating surface, which improves attraction properties,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling action at temperatures approaching 230°C and above...
• Possibility of accurate shaping as well as optimizing to specific applications,
• Versatile presence in high-tech industry – they serve a role in hard drives, motor assemblies, medical devices, and other advanced devices.
• 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 protecting magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets lose their power 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• Limited possibility of producing nuts in the magnet and complicated shapes - recommended is casing - magnetic holder.
• Possible danger to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the context of child health protection. Additionally, small components of these products are able to be problematic in diagnostics medical when they are in the body.
• With mass production the cost of neodymium magnets is economically unviable,

Optimal lifting capacity of a neodymium magnet – what contributes to it?

The declared magnet strength represents the peak performance, obtained under optimal environment, specifically:

• using a base made of low-carbon steel, serving as a magnetic yoke
• with a cross-section of at least 10 mm
• with a plane cleaned and smooth
• under conditions of gap-free contact (surface-to-surface)
• under vertical application of breakaway force (90-degree angle)
• in stable room temperature

Determinants of lifting force in real conditions

In practice, the actual lifting capacity is determined by several key aspects, ranked from most significant:

• Space between surfaces – every millimeter of distance (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is obtained only during perpendicular pulling. The force required to slide of the magnet along the plate is standardly several times smaller (approx. 1/5 of the lifting capacity).
• Steel thickness – too thin sheet does not accept the full field, causing part of the flux to be lost to the other side.
• Steel grade – ideal substrate is pure iron steel. Cast iron may attract less.
• Plate texture – smooth surfaces guarantee perfect abutment, which improves field saturation. Rough surfaces reduce efficiency.
• Heat – neodymium magnets 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).

* Lifting capacity was assessed using a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, however under parallel forces the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.