UMH 60x15x69 [M8] / N38 - magnetic holder with hook

Advantages and disadvantages of NdFeB magnets.

Besides their remarkable pulling force, neodymium magnets offer the following advantages:

• Their power is maintained, and after around ten years it drops only by ~1% (theoretically),
• Neodymium magnets are exceptionally resistant to loss of magnetic properties caused by magnetic disturbances,
• By applying a decorative coating of nickel, the element has an modern look,
• Magnetic induction on the working part of the magnet remains exceptional,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to freedom in constructing and the ability to customize to individual projects,
• Universal use in modern industrial fields – they serve a role in magnetic memories, electromotive mechanisms, diagnostic systems, and complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: weaknesses and usage proposals

• To avoid cracks under impact, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in producing threads and complicated forms in magnets, we propose using cover - magnetic mechanism.
• Potential hazard related to microscopic parts of magnets pose a threat, in case of ingestion, which gains importance in the context of child health protection. Furthermore, tiny parts of these products can be problematic in diagnostics medical after entering the body.
• With large orders the cost of neodymium magnets is a challenge,

Magnetic strength at its maximum – what it depends on?

The specified lifting capacity concerns the peak performance, recorded under laboratory conditions, meaning:

• with the use of a sheet made of low-carbon steel, guaranteeing maximum field concentration
• with a cross-section minimum 10 mm
• with an polished touching surface
• with total lack of distance (without coatings)
• for force acting at a right angle (pull-off, not shear)
• in stable room temperature

Practical aspects of lifting capacity – factors

During everyday use, the actual lifting capacity results from several key aspects, listed from most significant:

• Space between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Steel thickness – insufficiently thick steel causes magnetic saturation, causing part of the flux to be escaped to the other side.
• Material composition – different alloys reacts the same. High carbon content worsen the interaction with the magnet.
• Base smoothness – the more even the plate, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Thermal environment – heating the magnet results in weakening of induction. Check the thermal limit for a given model.

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under a perpendicular pulling force, in contrast under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate lowers the load capacity.