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

Advantages and disadvantages of NdFeB magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• Their strength remains stable, and after approximately 10 years it drops only by ~1% (according to research),
• Magnets very well protect themselves against demagnetization caused by external fields,
• Thanks to the metallic finish, the plating of Ni-Cu-Ni, gold-plated, or silver gives an visually attractive appearance,
• The surface of neodymium magnets generates a concentrated magnetic field – this is a distinguishing feature,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Possibility of custom creating and modifying to individual conditions,
• Wide application in modern industrial fields – they are commonly used in computer drives, electromotive mechanisms, precision medical tools, and multitasking production systems.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Disadvantages of neodymium magnets:

• To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium magnets lose their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• They oxidize in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited ability of producing threads in the magnet and complex forms - preferred is cover - mounting mechanism.
• Potential hazard to health – tiny shards of magnets can be dangerous, if swallowed, which becomes key in the context of child health protection. It is also worth noting that small elements of these magnets can disrupt the diagnostic process medical in case of swallowing.
• With budget limitations the cost of neodymium magnets is economically unviable,

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

The load parameter shown represents the limit force, obtained under optimal environment, namely:

• with the contact of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a massiveness of min. 10 mm to ensure full flux closure
• with an polished contact surface
• under conditions of ideal adhesion (surface-to-surface)
• during pulling in a direction vertical to the plane
• at temperature approx. 20 degrees Celsius

What influences lifting capacity in practice

Real force is affected by working environment parameters, including (from most important):

• Clearance – the presence of any layer (rust, dirt, air) acts as an insulator, which lowers power steeply (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to pulling vertically. When slipping, the magnet holds significantly lower power (often approx. 20-30% of maximum force).
• Plate thickness – insufficiently thick plate does not close the flux, causing part of the flux to be wasted to the other side.
• Plate material – low-carbon steel gives the best results. Higher carbon content reduce magnetic properties and holding force.
• Surface finish – ideal contact is possible only on polished steel. Any scratches and bumps create air cushions, weakening the magnet.
• Thermal factor – high temperature weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under perpendicular forces, in contrast under shearing force the load capacity is reduced by as much as fivefold. Additionally, even a small distance {between} the magnet’s surface and the plate reduces the holding force.