UI 45x13x6 [C323] / N38 - badge holder

Pros as well as cons of neodymium magnets.

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

• They virtually do not lose strength, because even after ten years the performance loss is only ~1% (in laboratory conditions),
• They are extremely resistant to demagnetization induced by presence of other magnetic fields,
• By applying a shiny layer of silver, the element acquires an aesthetic look,
• The surface of neodymium magnets generates a unique magnetic field – this is one of their assets,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Thanks to freedom in forming and the ability to modify to individual projects,
• Significant place in high-tech industry – they are commonly used in mass storage devices, electric motors, medical equipment, also complex engineering applications.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

What to avoid - cons of neodymium magnets and proposals for their use:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also improves its resistance to damage
• When exposed to high temperature, neodymium magnets suffer a drop in strength. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They oxidize in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited possibility of making nuts in the magnet and complicated forms - recommended is a housing - magnetic holder.
• Health risk resulting from small fragments of magnets can be dangerous, if swallowed, which becomes key in the aspect of protecting the youngest. Additionally, small elements of these devices are able to disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which hinders application in large quantities

Optimal lifting capacity of a neodymium magnet – what contributes to it?

The force parameter is a theoretical maximum value conducted under standard conditions:

• using a plate made of mild steel, functioning as a ideal flux conductor
• with a cross-section minimum 10 mm
• with an ideally smooth contact surface
• with total lack of distance (no coatings)
• for force applied at a right angle (in the magnet axis)
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

Effective lifting capacity impacted by specific conditions, mainly (from priority):

• Distance – the presence of any layer (rust, tape, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is available only during perpendicular pulling. The shear force of the magnet along the plate is standardly several times smaller (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of converting into lifting capacity.
• Chemical composition of the base – low-carbon steel gives the best results. Higher carbon content decrease magnetic permeability and lifting capacity.
• Surface structure – the more even the plate, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Operating temperature – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures gain strength (up to a certain limit).

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under attempts to slide the magnet the holding force is lower. In addition, even a small distance {between} the magnet’s surface and the plate decreases the load capacity.