UMP 97x40 [M8+M10] GW F300 kg / N38 - search holder

Advantages as well as disadvantages of rare earth magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They have unchanged lifting capacity, and over nearly 10 years their performance decreases symbolically – ~1% (according to theory),
• They are noted for resistance to demagnetization induced by external magnetic fields,
• In other words, due to the glossy finish of gold, the element becomes visually attractive,
• Magnets possess maximum magnetic induction on the active area,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Possibility of exact machining as well as adjusting to specific needs,
• Key role in modern industrial fields – they are commonly used in data components, electric motors, precision medical tools, and technologically advanced constructions.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Drawbacks and weaknesses of neodymium magnets and ways of using them

• At very strong impacts they can break, therefore we recommend 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.
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• Limited ability of making threads in the magnet and complicated shapes - recommended is a housing - mounting mechanism.
• Health risk to health – tiny shards of magnets pose a threat, in case of ingestion, which gains importance in the context of child safety. Furthermore, small components of these devices can be problematic in diagnostics medical in case of swallowing.
• With large orders the cost of neodymium magnets can be a barrier,

Highest magnetic holding force – what contributes to it?

The load parameter shown represents the peak performance, measured under ideal test conditions, meaning:

• with the use of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by smoothness
• under conditions of no distance (metal-to-metal)
• for force acting at a right angle (pull-off, not shear)
• in temp. approx. 20°C

Lifting capacity in real conditions – factors

During everyday use, the real power depends on many variables, presented from crucial:

• Space between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is reached only during pulling at a 90° angle. The shear force of the magnet along the plate is typically many times smaller (approx. 1/5 of the lifting capacity).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of converting into lifting capacity.
• Steel grade – ideal substrate is pure iron steel. Cast iron may generate lower lifting capacity.
• Surface finish – ideal contact is obtained only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Holding force was measured on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under shearing force the load capacity is reduced by as much as fivefold. Moreover, even a slight gap {between} the magnet and the plate reduces the load capacity.