UMP 75x25 [M10x3] GW F200 GOLD Lina / N42 - search holder

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their immense field intensity, neodymium magnets offer the following advantages:

• They virtually do not lose strength, because even after ten years, the performance loss is only ~1% (based on calculations),
• They remain magnetized despite exposure to magnetic noise,
• Because of the reflective layer of silver, the component looks visually appealing,
• Magnetic induction on the surface of these magnets is impressively powerful,
• Thanks to their enhanced temperature resistance, they can operate (depending on the geometry) even at temperatures up to 230°C or more,
• The ability for accurate shaping and adjustment to custom needs – neodymium magnets can be manufactured in many forms and dimensions, which amplifies their functionality across industries,
• Key role in new technology industries – they are utilized in hard drives, electric motors, diagnostic apparatus or even high-tech tools,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in tiny dimensions, which makes them ideal in compact constructions

Disadvantages of NdFeB magnets:

• They can break when subjected to a sudden impact. If the magnets are exposed to shocks, we recommend in a steel housing. The steel housing, in the form of a holder, protects the magnet from cracks and additionally enhances its overall durability,
• They lose field intensity at high temperatures. Most neodymium magnets experience permanent decline in strength when heated above 80°C (depending on the form and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Magnets exposed to wet conditions can rust. Therefore, for outdoor applications, we suggest waterproof types made of non-metallic composites,
• Limited ability to create threads in the magnet – the use of a housing is recommended,
• Possible threat related to magnet particles may arise, in case of ingestion, which is notable in the protection of children. Furthermore, small elements from these devices have the potential to interfere with diagnostics if inside the body,
• In cases of tight budgets, neodymium magnet cost may not be economically viable,

Maximum lifting capacity of the magnet – what contributes to it?

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

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• with a thickness of minimum 10 mm
• with a polished side
• with zero air gap
• with vertical force applied
• in normal thermal conditions

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, because 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 carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, whereas under parallel forces the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.