MPL 5x5x1.5 / N38 - lamellar magnet

Advantages as well as disadvantages of neodymium magnets.

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

• They do not lose strength, even during approximately 10 years – the reduction in lifting capacity is only ~1% (based on measurements),
• Magnets very well protect themselves against loss of magnetization caused by external fields,
• By covering with a lustrous coating of silver, the element has an proper look,
• Magnets are distinguished by exceptionally strong magnetic induction on the active area,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of accurate modeling as well as adapting to individual needs,
• Versatile presence in modern technologies – they serve a role in computer drives, motor assemblies, medical equipment, also multitasking production systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets decrease their strength 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
• We suggest a housing - magnetic holder, due to difficulties in producing threads inside the magnet and complex shapes.
• Health risk related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which becomes key in the context of child safety. Additionally, small elements of these magnets are able to complicate diagnosis medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what it depends on?

Breakaway force was defined for ideal contact conditions, assuming:

• using a base made of low-carbon steel, acting as a magnetic yoke
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with a plane free of scratches
• under conditions of no distance (metal-to-metal)
• under vertical application of breakaway force (90-degree angle)
• at conditions approx. 20°C

Determinants of lifting force in real conditions

Holding efficiency impacted by specific conditions, including (from most important):

• Space between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – highest force is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of converting into lifting capacity.
• Steel type – mild steel gives the best results. Higher carbon content decrease magnetic properties and holding force.
• Plate texture – smooth surfaces ensure maximum contact, which improves force. Uneven metal reduce efficiency.
• Thermal factor – hot environment reduces magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under perpendicular forces, whereas under attempts to slide the magnet the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.