UMT 12x20 black set / N38 - board holder

Strengths and weaknesses of neodymium magnets.

Apart from their strong magnetism, neodymium magnets have these key benefits:

• Their strength remains stable, and after approximately ten years it decreases only by ~1% (according to research),
• They feature excellent resistance to weakening of magnetic properties as a result of external fields,
• A magnet with a smooth gold surface looks better,
• Magnets are distinguished by excellent magnetic induction on the working surface,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Considering the option of flexible molding and adaptation to custom needs, magnetic components can be manufactured in a variety of geometric configurations, which increases their versatility,
• Versatile presence in modern industrial fields – they are utilized in mass storage devices, electric motors, precision medical tools, also multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which enables their usage in compact constructions

Disadvantages of neodymium magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We recommend cover - magnetic mechanism, due to difficulties in producing threads inside the magnet and complicated shapes.
• Health risk related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. Additionally, small components of these products can be problematic in diagnostics medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which hinders application in large quantities

Detachment force of the magnet in optimal conditions – what contributes to it?

The declared magnet strength concerns the maximum value, recorded under laboratory conditions, specifically:

• using a plate made of low-carbon steel, functioning as a circuit closing element
• whose thickness is min. 10 mm
• with an ideally smooth touching surface
• with direct contact (no coatings)
• under vertical application of breakaway force (90-degree angle)
• in stable room temperature

Practical aspects of lifting capacity – factors

Bear in mind that the working load may be lower influenced by elements below, in order of importance:

• Space between surfaces – every millimeter of separation (caused e.g. by veneer or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Load vector – highest force is reached only during pulling at a 90° angle. The force required to slide of the magnet along the plate is standardly many times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Steel type – mild steel gives the best results. Alloy admixtures decrease magnetic permeability and lifting capacity.
• Surface condition – smooth surfaces ensure maximum contact, which increases field saturation. Uneven metal reduce efficiency.
• Temperature influence – hot environment weakens pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Holding force was measured on the plate surface of 20 mm thickness, when the force acted perpendicularly, whereas under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the holding force.