HH 16x5.3 [M3] / N38 - through hole magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They do not lose their even during around ten years – the loss of strength is only ~1% (theoretically),
• They are very resistant to demagnetization caused by external field interference,
• By applying a reflective layer of gold, the element gains a modern look,
• They exhibit extremely high levels of magnetic induction near the outer area of the magnet,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• The ability for precise shaping and customization to custom needs – neodymium magnets can be manufactured in multiple variants of geometries, which enhances their versatility in applications,
• Important function in advanced technical fields – they find application in data storage devices, electric motors, clinical machines and high-tech tools,
• Thanks to their power density, small magnets offer high magnetic performance, while occupying minimal space,

Disadvantages of magnetic elements:

• They can break when subjected to a sudden impact. If the magnets are exposed to physical collisions, they should be placed in a protective case. The steel housing, in the form of a holder, protects the magnet from fracture and additionally strengthens its overall resistance,
• Magnets lose power when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible field weakening (influenced by the magnet’s dimensions). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• They rust in a damp environment, especially when used outside, we recommend using encapsulated magnets, such as those made of plastic,
• Using a cover – such as a magnetic holder – is advised due to the limitations in manufacturing complex structures directly in the magnet,
• Health risk due to small fragments may arise, if ingested accidentally, which is significant in the context of child safety. It should also be noted that small elements from these assemblies can hinder health screening when ingested,
• In cases of mass production, neodymium magnet cost is a challenge,

Breakaway strength of the magnet in ideal conditions – what affects it?

The given pulling force of the magnet means the maximum force, determined under optimal conditions, namely:

• with the use of low-carbon steel plate serving as a magnetic yoke
• of a thickness of at least 10 mm
• with a smooth surface
• with zero air gap
• under perpendicular detachment force
• under standard ambient temperature

Impact of factors on magnetic holding capacity in practice

The lifting capacity of a magnet is influenced by in practice the following factors, ordered from most important to least 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 performed on a smooth plate of suitable thickness, under perpendicular forces, however under shearing force the holding force is lower. Moreover, even a minimal clearance {between} the magnet’s surface and the plate lowers the load capacity.