NCM 10x13.5x5 / N38 - channel magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They have stable power, and over around 10 years their performance decreases symbolically – ~1% (according to theory),
• They protect against demagnetization induced by ambient magnetic influence remarkably well,
• Because of the reflective layer of silver, the component looks high-end,
• They possess significant magnetic force measurable at the magnet’s surface,
• Neodymium magnets are known for exceptionally strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the magnetic form),
• Thanks to the freedom in shaping and the capability to adapt to individual requirements, neodymium magnets can be created in various configurations, which increases their application range,
• Important function in advanced technical fields – they serve a purpose in hard drives, electromechanical systems, diagnostic apparatus as well as sophisticated instruments,
• Relatively small size with high magnetic force – neodymium magnets offer intense magnetic field in tiny dimensions, which makes them useful in small systems

Disadvantages of neodymium magnets:

• They may fracture when subjected to a heavy impact. If the magnets are exposed to shocks, we recommend in a protective case. The steel housing, in the form of a holder, protects the magnet from damage , and at the same time reinforces its overall resistance,
• Magnets lose power when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible magnetic decay (influenced by the magnet’s profile). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Due to corrosion risk in humid conditions, it is recommended to use sealed magnets made of rubber for outdoor use,
• Limited ability to create threads in the magnet – the use of a magnetic holder is recommended,
• Health risk from tiny pieces may arise, if ingested accidentally, which is notable in the context of child safety. Additionally, miniature parts from these assemblies might interfere with diagnostics after being swallowed,
• In cases of large-volume purchasing, neodymium magnet cost may not be economically viable,

Optimal lifting capacity of a neodymium magnet – what affects it?

The given strength of the magnet represents the optimal strength, determined in ideal conditions, that is:

• with the use of low-carbon steel plate serving as a magnetic yoke
• having a thickness of no less than 10 millimeters
• with a refined outer layer
• in conditions of no clearance
• with vertical force applied
• under standard ambient temperature

Practical aspects of lifting capacity – factors

The lifting capacity of a magnet is influenced by in practice the following factors, according to their importance:

• 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.

* Holding force was tested on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under shearing force the holding force is lower. Additionally, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.