AM lina fi 10 mm - magnetic accessories

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• They do not lose their even during nearly 10 years – the reduction of power is only ~1% (based on measurements),
• They show superior resistance to demagnetization from external magnetic fields,
• Because of the brilliant layer of nickel, the component looks high-end,
• They have extremely strong magnetic induction on the surface of the magnet,
• These magnets tolerate extreme temperatures, often exceeding 230°C, when properly designed (in relation to form),
• With the option for fine forming and targeted design, these magnets can be produced in various shapes and sizes, greatly improving engineering flexibility,
• Important function in new technology industries – they find application in hard drives, electric motors, medical equipment or even other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in compact dimensions, which makes them ideal in small systems

Disadvantages of NdFeB magnets:

• They are prone to breaking when subjected to a strong impact. If the magnets are exposed to external force, we recommend in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from fracture and additionally strengthens its overall strength,
• High temperatures may significantly reduce the magnetic power of neodymium magnets. Typically, above 80°C, they experience permanent decline in performance (depending on shape). To prevent this, we offer heat-resistant magnets marked [AH], capable of working up to 230°C, which makes them perfect for high-temperature use,
• Magnets exposed to moisture can rust. Therefore, for outdoor applications, we suggest waterproof types made of non-metallic composites,
• Limited ability to create precision features in the magnet – the use of a external casing is recommended,
• Health risk linked to microscopic shards may arise, in case of ingestion, which is crucial in the protection of children. Moreover, tiny components from these devices might hinder health screening if inside the body,
• High unit cost – neodymium magnets are pricier than other types of magnets (e.g., ferrite), which may limit large-scale applications

Maximum lifting capacity of the magnet – what affects it?

The given pulling force of the magnet means the maximum force, determined in the best circumstances, that is:

• using a steel plate with low carbon content, serving as a magnetic circuit closure
• with a thickness of minimum 10 mm
• with a polished side
• in conditions of no clearance
• in a perpendicular direction of force
• in normal thermal conditions

Determinants of practical lifting force of a magnet

The lifting capacity of a magnet depends on in practice key elements, according to their importance:

• 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 using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular pulling force, however under parallel forces the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet’s surface and the plate lowers the load capacity.