KM HF - 22 kg - magnetic bracket

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their tremendous strength, neodymium magnets offer the following advantages:

• They retain their magnetic properties for almost ten years – the drop is just ~1% (based on simulations),
• Their ability to resist magnetic interference from external fields is notable,
• The use of a decorative nickel surface provides a eye-catching finish,
• They have exceptional magnetic induction on the surface of the magnet,
• With the right combination of magnetic alloys, they reach increased thermal stability, enabling operation at or above 230°C (depending on the form),
• With the option for tailored forming and precise design, these magnets can be produced in multiple shapes and sizes, greatly improving application potential,
• Significant impact in new technology industries – they serve a purpose in HDDs, electric drives, clinical machines as well as technologically developed systems,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in compact dimensions, which makes them useful in compact constructions

Disadvantages of magnetic elements:

• They are prone to breaking when subjected to a sudden impact. If the magnets are exposed to physical collisions, we recommend in a metal holder. The steel housing, in the form of a holder, protects the magnet from breakage and enhances its overall strength,
• Magnets lose power when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible field weakening (influenced by the magnet’s dimensions). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• They rust in a humid environment, especially when used outside, we recommend using sealed magnets, such as those made of polymer,
• Limited ability to create precision features in the magnet – the use of a external casing is recommended,
• Health risk due to small fragments may arise, especially if swallowed, which is important in the context of child safety. It should also be noted that minuscule fragments from these assemblies might interfere with diagnostics if inside the body,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

Maximum lifting capacity of the magnet – what affects it?

The given strength of the magnet represents the optimal strength, calculated in ideal conditions, namely:

• with mild steel, used as a magnetic flux conductor
• with a thickness of minimum 10 mm
• with a polished side
• in conditions of no clearance
• under perpendicular detachment force
• at room temperature

Practical aspects of lifting capacity – factors

Practical lifting force is determined by factors, listed from the most critical to the less significant:

• Air gap between the magnet and the plate, since even a very small distance (e.g. 0.5 mm) can cause 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.

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Additionally, even a small distance {between} the magnet’s surface and the plate lowers the load capacity.