RM R4 - 5000 Gs / N52 - magnetic distributor

Advantages and disadvantages of neodymium magnets NdFeB.

Apart from their superior magnetic energy, neodymium magnets have these key benefits:

• They retain their full power for nearly ten years – the drop is just ~1% (based on simulations),
• They show superior resistance to demagnetization from outside magnetic sources,
• Because of the brilliant layer of nickel, the component looks aesthetically refined,
• Magnetic induction on the surface of these magnets is very strong,
• Thanks to their enhanced temperature resistance, they can operate (depending on the form) even at temperatures up to 230°C or more,
• The ability for precise shaping as well as customization to custom needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which enhances their versatility in applications,
• Important function in new technology industries – they find application in HDDs, electric motors, diagnostic apparatus along with sophisticated instruments,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in small dimensions, which makes them ideal in compact constructions

Disadvantages of magnetic elements:

• They can break when subjected to a sudden impact. If the magnets are exposed to external force, we recommend in a protective case. The steel housing, in the form of a holder, protects the magnet from breakage while also strengthens its overall robustness,
• They lose field intensity at elevated temperatures. Most neodymium magnets experience permanent loss in strength when heated above 80°C (depending on the geometry and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• They rust in a humid environment – during outdoor use, we recommend using sealed magnets, such as those made of rubber,
• The use of a protective casing or external holder is recommended, since machining internal cuts in neodymium magnets is risky,
• Health risk due to small fragments may arise, when consumed by mistake, which is significant in the protection of children. Additionally, miniature parts from these magnets might interfere with diagnostics after being swallowed,
• In cases of mass production, neodymium magnet cost may not be economically viable,

Maximum magnetic pulling force – what contributes to it?

The given lifting capacity of the magnet represents the maximum lifting force, determined in ideal 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 refined outer layer
• with no separation
• in a perpendicular direction of force
• at room temperature

What influences lifting capacity in practice

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

• Air gap between the magnet and the plate, as 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 was determined with the use of a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, in contrast under shearing force the load capacity is reduced by as much as fivefold. Moreover, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.