UMP 65x45 [M8] GW - search holder

Strengths as well as weaknesses of NdFeB magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (according to literature),
• They do not lose their magnetic properties even under strong external field,
• The use of an shiny layer of noble metals (nickel, gold, silver) causes the element to look better,
• The surface of neodymium magnets generates a strong magnetic field – this is one of their assets,
• 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...
• Thanks to flexibility in constructing and the capacity to customize to individual projects,
• Significant place in modern industrial fields – they serve a role in hard drives, electric motors, diagnostic systems, and complex engineering applications.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons of neodymium magnets: application proposals

• 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.
• When exposed to high temperature, neodymium magnets suffer a drop in force. 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• Limited ability of producing threads in the magnet and complicated shapes - recommended is casing - magnet mounting.
• Health risk to health – tiny shards of magnets are risky, if swallowed, which is particularly important in the aspect of protecting the youngest. Additionally, small elements of these magnets are able to complicate diagnosis medical when they are in the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which hinders application in large quantities

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

The force parameter is a theoretical maximum value executed under standard conditions:

• with the contact of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• whose thickness reaches at least 10 mm
• with a surface free of scratches
• without the slightest air gap between the magnet and steel
• during pulling in a direction perpendicular to the mounting surface
• at standard ambient temperature

Key elements affecting lifting force

Effective lifting capacity is influenced by working environment parameters, including (from most important):

• Distance – existence of foreign body (rust, dirt, air) acts as an insulator, which reduces capacity steeply (even by 50% at 0.5 mm).
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Material type – the best choice is pure iron steel. Cast iron may generate lower lifting capacity.
• Smoothness – ideal contact is possible only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Thermal factor – hot environment weakens pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a slight gap {between} the magnet and the plate decreases the lifting capacity.