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

Advantages and disadvantages of NdFeB magnets.

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

• They have constant strength, and over around 10 years their attraction force decreases symbolically – ~1% (in testing),
• They maintain their magnetic properties even under close interference source,
• The use of an aesthetic finish of noble metals (nickel, gold, silver) causes the element to look better,
• Neodymium magnets create maximum magnetic induction on a small surface, which ensures high operational effectiveness,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Possibility of detailed forming as well as adapting to individual conditions,
• Versatile presence in future technologies – they find application in hard drives, brushless drives, medical devices, as well as modern systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• At very strong impacts they can crack, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• Limited possibility of creating threads in the magnet and complex shapes - preferred is cover - magnetic holder.
• Potential hazard resulting from small fragments of magnets pose a threat, in case of ingestion, which is particularly important in the context of child health protection. It is also worth noting that tiny parts of these products can be problematic in diagnostics 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 it depends on?

The load parameter shown represents the peak performance, obtained under ideal test conditions, namely:

• on a base made of mild steel, effectively closing the magnetic flux
• whose transverse dimension equals approx. 10 mm
• characterized by even structure
• without any insulating layer between the magnet and steel
• for force applied at a right angle (in the magnet axis)
• in temp. approx. 20°C

Lifting capacity in real conditions – factors

In real-world applications, the real power depends on many variables, presented from the most important:

• Distance – existence of any layer (rust, dirt, air) acts as an insulator, which reduces power rapidly (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to pulling vertically. When slipping, the magnet exhibits much less (often approx. 20-30% of nominal force).
• Steel thickness – insufficiently thick plate causes magnetic saturation, causing part of the power to be escaped into the air.
• Metal type – different alloys attracts identically. Alloy additives worsen the attraction effect.
• Smoothness – full contact is possible only on polished steel. Rough texture reduce the real contact area, weakening the magnet.
• Thermal environment – heating the magnet causes a temporary drop of induction. Check the maximum operating temperature for a given model.

* Lifting capacity was assessed with the use of a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, however under shearing force the load capacity is reduced by as much as fivefold. Moreover, even a slight gap {between} the magnet and the plate decreases the load capacity.