UMS 20x8.6x4.5x7 / N38 - conical magnetic holder

Strengths as well as weaknesses of NdFeB magnets.

Besides their remarkable magnetic power, neodymium magnets offer the following advantages:

• They do not lose strength, even during approximately 10 years – the decrease in strength is only ~1% (according to tests),
• They have excellent resistance to magnetism drop when exposed to external magnetic sources,
• In other words, due to the metallic layer of gold, the element gains visual value,
• The surface of neodymium magnets generates a concentrated magnetic field – this is a distinguishing feature,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures reaching 230°C and above...
• In view of the option of flexible molding and customization to individualized requirements, neodymium magnets can be modeled in a wide range of geometric configurations, which expands the range of possible applications,
• Fundamental importance in electronics industry – they are utilized in magnetic memories, electric motors, medical equipment, as well as complex engineering applications.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium magnets lose power when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• They rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We suggest cover - magnetic holder, due to difficulties in creating nuts inside the magnet and complicated forms.
• Possible danger resulting from small fragments of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child safety. Additionally, tiny parts of these magnets are able to be problematic in diagnostics medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

The load parameter shown represents the limit force, measured under ideal test conditions, specifically:

• with the contact of a yoke made of low-carbon steel, guaranteeing maximum field concentration
• possessing a massiveness of min. 10 mm to avoid saturation
• with a plane cleaned and smooth
• with zero gap (no coatings)
• under perpendicular force direction (90-degree angle)
• at room temperature

Practical aspects of lifting capacity – factors

Bear in mind that the working load will differ subject to the following factors, in order of importance:

• Clearance – the presence of foreign body (rust, dirt, air) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Direction of force – highest force is reached only during pulling at a 90° angle. The shear force of the magnet along the surface is typically many times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Material composition – different alloys reacts the same. High carbon content worsen the interaction with the magnet.
• Smoothness – ideal contact is obtained only on polished steel. Rough texture create air cushions, weakening the magnet.
• Temperature influence – high temperature reduces pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity was measured using a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, however under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet’s surface and the plate reduces the load capacity.