UMP 75x24 [M8+M10] GW F 200 kg - search holder

Advantages as well as disadvantages of rare earth magnets.

Besides their tremendous pulling force, neodymium magnets offer the following advantages:

• They do not lose power, even over around ten years – the drop in strength is only ~1% (based on measurements),
• They retain their magnetic properties even under external field action,
• In other words, due to the aesthetic layer of nickel, the element gains a professional look,
• Magnetic induction on the working layer of the magnet remains strong,
• 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...
• Due to the potential of accurate molding and adaptation to individualized needs, magnetic components can be manufactured in a wide range of geometric configurations, which increases their versatility,
• Universal use in advanced technology sectors – they serve a role in hard drives, brushless drives, advanced medical instruments, and modern systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons of neodymium magnets and ways of using them

• At strong impacts they can crack, therefore we recommend placing them in special holders. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets decrease their force 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
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Limited possibility of creating nuts in the magnet and complex shapes - recommended is casing - magnetic holder.
• Health risk resulting from small fragments of magnets pose a threat, if swallowed, which gains importance in the context of child safety. It is also worth noting that small elements of these products are able to be problematic in diagnostics medical when they are in the body.
• Due to complex production process, their price exceeds standard values,

Magnetic strength at its maximum – what it depends on?

Holding force of 280 kg is a measurement result conducted under standard conditions:

• on a plate made of structural steel, perfectly concentrating the magnetic field
• whose transverse dimension equals approx. 10 mm
• with an ground contact surface
• without any air gap between the magnet and steel
• under vertical force vector (90-degree angle)
• in stable room temperature

Lifting capacity in real conditions – factors

During everyday use, the actual holding force depends on many variables, listed from most significant:

• Gap between surfaces – every millimeter of separation (caused e.g. by varnish or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – maximum parameter is available only during pulling at a 90° angle. The force required to slide of the magnet along the surface is typically several times smaller (approx. 1/5 of the lifting capacity).
• Steel thickness – too thin sheet does not accept the full field, causing part of the power to be wasted into the air.
• Material type – ideal substrate is pure iron steel. Cast iron may have worse magnetic properties.
• Surface condition – smooth surfaces guarantee perfect abutment, which increases force. Uneven metal weaken the grip.
• Temperature – heating the magnet causes a temporary drop of induction. Check the maximum operating temperature for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, whereas under parallel forces the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet’s surface and the plate decreases the holding force.