MW 38x3.5 / N38 - cylindrical magnet

Advantages as well as disadvantages of rare earth magnets.

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

• They do not lose strength, even after around 10 years – the drop in power is only ~1% (based on measurements),
• Magnets effectively defend themselves against loss of magnetization caused by external fields,
• In other words, due to the shiny finish of nickel, the element becomes visually attractive,
• They are known for high magnetic induction at the operating surface, which affects their 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 custom forming as well as optimizing to atypical needs,
• Fundamental importance in modern industrial fields – they are commonly used in HDD drives, motor assemblies, precision medical tools, also multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which allows their use in small systems

Disadvantages of NdFeB magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• They oxidize in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing threads and complex forms in magnets, we propose using casing - magnetic mount.
• Health risk resulting from small fragments of magnets are risky, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, tiny parts of these magnets are able to be problematic in diagnostics medical when they are in the body.
• Due to expensive raw materials, their price exceeds standard values,

Maximum lifting force for a neodymium magnet – what contributes to it?

Information about lifting capacity was determined for ideal contact conditions, including:

• using a base made of high-permeability steel, serving as a ideal flux conductor
• whose thickness reaches at least 10 mm
• characterized by smoothness
• without any insulating layer between the magnet and steel
• during pulling in a direction vertical to the plane
• at temperature approx. 20 degrees Celsius

Practical lifting capacity: influencing factors

It is worth knowing that the working load will differ influenced by elements below, in order of importance:

• Clearance – existence of any layer (paint, dirt, air) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to pulling vertically. When slipping, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Element thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Material type – the best choice is high-permeability steel. Stainless steels may generate lower lifting capacity.
• Plate texture – smooth surfaces ensure maximum contact, which improves force. Rough surfaces weaken the grip.
• Thermal environment – heating the magnet results in weakening of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity testing was carried out on a smooth plate of optimal thickness, under perpendicular forces, in contrast under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet’s surface and the plate lowers the holding force.