MW 14x10 / N38 - cylindrical magnet

Strengths and weaknesses of rare earth magnets.

Besides their exceptional field intensity, neodymium magnets offer the following advantages:

• They do not lose strength, even over around 10 years – the drop in power is only ~1% (based on measurements),
• Magnets very well protect themselves against loss of magnetization caused by external fields,
• In other words, due to the metallic layer of nickel, the element gains a professional look,
• The surface of neodymium magnets generates a powerful 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 versatility in shaping and the capacity to customize to complex applications,
• Versatile presence in modern industrial fields – they serve a role in data components, electromotive mechanisms, precision medical tools, as well as modern systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons of neodymium magnets: application proposals

• At strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• When exposed to high temperature, neodymium magnets experience 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
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited ability of producing threads in the magnet and complex shapes - preferred is cover - mounting mechanism.
• Health risk related to microscopic parts of magnets can be dangerous, if swallowed, which becomes key in the context of child safety. Additionally, small elements of these products are able to complicate diagnosis medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum lifting force for a neodymium magnet – what affects it?

The lifting capacity listed is a result of laboratory testing executed under specific, ideal conditions:

• with the use of a yoke made of low-carbon steel, ensuring maximum field concentration
• possessing a massiveness of at least 10 mm to avoid saturation
• with a surface free of scratches
• without any air gap between the magnet and steel
• under perpendicular application of breakaway force (90-degree angle)
• in temp. approx. 20°C

Magnet lifting force in use – key factors

Effective lifting capacity impacted by specific conditions, mainly (from priority):

• Space between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to pulling vertically. When attempting to slide, the magnet holds much less (typically approx. 20-30% of maximum force).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Steel type – mild steel attracts best. Alloy steels decrease magnetic properties and holding force.
• Smoothness – ideal contact is possible only on polished steel. Any scratches and bumps create air cushions, reducing force.
• Thermal factor – high temperature reduces magnetic field. Too high temperature can permanently demagnetize the magnet.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under shearing force the holding force is lower. Moreover, even a minimal clearance {between} the magnet’s surface and the plate reduces the holding force.