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

Strengths as well as weaknesses of neodymium magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• They have excellent resistance to weakening of magnetic properties as a result of opposing magnetic fields,
• The use of an shiny layer of noble metals (nickel, gold, silver) causes the element to look better,
• They show high magnetic induction at the operating surface, making them more effective,
• 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...
• In view of the ability of accurate molding and adaptation to custom solutions, NdFeB magnets can be created in a broad palette of geometric configurations, which amplifies use scope,
• Huge importance in electronics industry – they are utilized in mass storage devices, electric drive systems, medical equipment, as well as other advanced devices.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets and proposals for their use:

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a special holder, which not only protects them against impacts but also increases their durability
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
• Limited possibility of producing threads in the magnet and complicated shapes - recommended is cover - magnetic holder.
• Health risk resulting from small fragments of magnets are risky, if swallowed, which is particularly important in the context of child safety. It is also worth noting that small components of these magnets are able to disrupt the diagnostic process medical in case of swallowing.
• Due to neodymium price, their price exceeds standard values,

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

The lifting capacity listed is a theoretical maximum value performed under the following configuration:

• with the contact of a sheet made of special test steel, guaranteeing maximum field concentration
• with a thickness minimum 10 mm
• with a surface cleaned and smooth
• without the slightest clearance between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• in temp. approx. 20°C

Practical lifting capacity: influencing factors

Holding efficiency impacted by working environment parameters, such as (from priority):

• Gap between magnet and steel – every millimeter of distance (caused e.g. by veneer or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Steel thickness – insufficiently thick plate does not accept the full field, causing part of the power to be lost to the other side.
• Material composition – different alloys reacts the same. Alloy additives worsen the interaction with the magnet.
• Smoothness – full contact is obtained only on polished steel. Rough texture reduce the real contact area, reducing force.
• Temperature – heating the magnet results in weakening of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was measured by applying a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, in contrast under parallel forces the load capacity is reduced by as much as 75%. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.