HH 36x7.5 [M6] / N38 - through hole magnetic holder

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• They virtually do not lose power, because even after ten years, the performance loss is only ~1% (in laboratory conditions),
• They protect against demagnetization induced by external electromagnetic environments very well,
• In other words, due to the glossy silver coating, the magnet obtains an professional appearance,
• Magnetic induction on the surface of these magnets is very strong,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• Thanks to the possibility in shaping and the capability to adapt to unique requirements, neodymium magnets can be created in various configurations, which increases their usage potential,
• Important function in advanced technical fields – they are used in computer drives, rotating machines, healthcare devices as well as other advanced devices,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of magnetic elements:

• They can break when subjected to a powerful impact. If the magnets are exposed to physical collisions, it is suggested to place them in a metal holder. The steel housing, in the form of a holder, protects the magnet from breakage while also increases its overall durability,
• They lose power at increased temperatures. Most neodymium magnets experience permanent reduction in strength when heated above 80°C (depending on the dimensions 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. For outdoor use, we recommend using encapsulated magnets, such as those made of non-metallic materials,
• Limited ability to create internal holes in the magnet – the use of a external casing is recommended,
• Possible threat related to magnet particles may arise, especially if swallowed, which is notable in the protection of children. Moreover, minuscule fragments from these products may complicate medical imaging if inside the body,
• High unit cost – neodymium magnets are more expensive than other types of magnets (e.g., ferrite), which increases the cost of large-scale applications

Maximum lifting capacity of the magnet – what it depends on?

The given pulling force of the magnet means the maximum force, determined in ideal conditions, specifically:

• with mild steel, used as a magnetic flux conductor
• having a thickness of no less than 10 millimeters
• with a smooth surface
• in conditions of no clearance
• with vertical force applied
• at room temperature

Practical aspects of lifting capacity – factors

The lifting capacity of a magnet is influenced by in practice key elements, according to their importance:

• 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.

* Holding force was checked on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under parallel forces the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.