UMP 50x20 [M8] GW / N38 - search holder

Pros and cons of rare earth magnets.

Besides their remarkable strength, neodymium magnets offer the following advantages:

• They do not lose power, even after approximately ten years – the drop in power is only ~1% (theoretically),
• They are noted for resistance to demagnetization induced by presence of other magnetic fields,
• A magnet with a metallic gold surface has better aesthetics,
• The surface of neodymium magnets generates a powerful magnetic field – this is one of their assets,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• In view of the ability of flexible shaping and customization to specialized solutions, magnetic components can be created in a wide range of geometric configurations, which expands the range of possible applications,
• Wide application in modern technologies – they are utilized in HDD drives, brushless drives, medical devices, and industrial machines.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• Neodymium magnets decrease their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Due to limitations in realizing nuts and complex forms in magnets, we propose using casing - magnetic holder.
• Potential hazard resulting from small fragments of magnets pose a threat, if swallowed, which gains importance in the context of child health protection. Additionally, small components of these products can complicate diagnosis medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Breakaway strength of the magnet in ideal conditions – what contributes to it?

The load parameter shown refers to the peak performance, obtained under ideal test conditions, specifically:

• with the application of a sheet made of low-carbon steel, ensuring full magnetic saturation
• with a cross-section no less than 10 mm
• characterized by lack of roughness
• with zero gap (no paint)
• under perpendicular force vector (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

Determinants of practical lifting force of a magnet

Please note that the magnet holding may be lower subject to the following factors, starting with the most relevant:

• Distance – existence of foreign body (rust, dirt, gap) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to detachment vertically. When applying parallel force, the magnet holds much less (often approx. 20-30% of nominal force).
• Base massiveness – too thin sheet does not accept the full field, causing part of the flux to be lost into the air.
• Plate material – mild steel attracts best. Alloy steels lower magnetic permeability and holding force.
• Surface finish – full contact is possible only on polished steel. Rough texture reduce the real contact area, reducing force.
• Heat – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under parallel forces the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.