UMP 94x40 [3xM10] GW F550 Silver Black / N52 - search holder

Advantages as well as disadvantages of rare earth magnets.

Besides their immense field intensity, neodymium magnets offer the following advantages:

• They have stable power, and over nearly 10 years their attraction force decreases symbolically – ~1% (according to theory),
• They have excellent resistance to weakening of magnetic properties as a result of opposing magnetic fields,
• The use of an shiny coating of noble metals (nickel, gold, silver) causes the element to present itself better,
• They feature high magnetic induction at the operating surface, which improves attraction properties,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Thanks to modularity in constructing and the ability to adapt to specific needs,
• Significant place in modern industrial fields – they are used in computer drives, electric drive systems, diagnostic systems, also complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets and proposals for their use:

• At strong impacts they can crack, therefore we advise placing them in strong housings. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• We warn that neodymium magnets can lose 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 realizing nuts and complicated shapes in magnets, we recommend using casing - magnetic mechanism.
• Potential hazard resulting from small fragments of magnets are risky, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Additionally, small elements of these products can disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Maximum lifting force for a neodymium magnet – what affects it?

The force parameter is a theoretical maximum value performed under specific, ideal conditions:

• with the use of a sheet made of low-carbon steel, guaranteeing maximum field concentration
• possessing a massiveness of minimum 10 mm to ensure full flux closure
• with an ideally smooth contact surface
• with total lack of distance (no impurities)
• during pulling in a direction vertical to the plane
• at temperature approx. 20 degrees Celsius

What influences lifting capacity in practice

It is worth knowing that the application force will differ influenced by elements below, starting with the most relevant:

• Gap between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Force direction – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Steel grade – ideal substrate is high-permeability steel. Hardened steels may generate lower lifting capacity.
• Surface condition – smooth surfaces guarantee perfect abutment, which increases force. Rough surfaces reduce efficiency.
• Heat – NdFeB sinters have a sensitivity to temperature. When it is hot they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was assessed using a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under parallel forces the holding force is lower. Additionally, even a small distance {between} the magnet and the plate reduces the holding force.