KM HF - 22 kg - magnetic bracket

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They virtually do not lose power, because even after ten years, the performance loss is only ~1% (according to literature),
• They protect against demagnetization induced by ambient magnetic influence remarkably well,
• The use of a polished silver surface provides a eye-catching finish,
• The outer field strength of the magnet shows remarkable magnetic properties,
• Neodymium magnets are known for very high magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the shape),
• The ability for custom shaping as well as adaptation to custom needs – neodymium magnets can be manufactured in many forms and dimensions, which amplifies their functionality across industries,
• Important function in modern technologies – they find application in HDDs, electromechanical systems, healthcare devices along with sophisticated instruments,
• Compactness – despite their small size, they provide high effectiveness, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are prone to breaking when subjected to a sudden impact. If the magnets are exposed to physical collisions, it is advisable to use in a protective case. The steel housing, in the form of a holder, protects the magnet from breakage , and at the same time strengthens its overall strength,
• They lose magnetic force at extreme temperatures. Most neodymium magnets experience permanent degradation in strength when heated above 80°C (depending on the shape and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Due to corrosion risk in humid conditions, it is advisable to use sealed magnets made of protective material for outdoor use,
• The use of a protective casing or external holder is recommended, since machining threads in neodymium magnets is restricted,
• Health risk related to magnet particles may arise, if ingested accidentally, which is crucial in the family environments. Moreover, tiny components from these devices can complicate medical imaging once in the system,
• In cases of large-volume purchasing, neodymium magnet cost may be a barrier,

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

The given strength of the magnet represents the optimal strength, calculated under optimal conditions, specifically:

• using a steel plate with low carbon content, serving as a magnetic circuit closure
• of a thickness of at least 10 mm
• with a polished side
• in conditions of no clearance
• in a perpendicular direction of force
• under standard ambient temperature

Practical lifting capacity: influencing factors

Practical lifting force is dependent on factors, by priority:

• Air gap between the magnet and the plate, since even a very small distance (e.g. 0.5 mm) causes a drop in lifting force of up to 50%.
• Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
• Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
• Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
• Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
• Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under shearing force the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet’s surface and the plate reduces the lifting capacity.