MW 6x1 / N38 - cylindrical magnet

Pros and cons of rare earth magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They retain full power for almost 10 years – the loss is just ~1% (based on simulations),
• They have excellent resistance to magnetism drop when exposed to opposing magnetic fields,
• In other words, due to the metallic surface of silver, the element becomes visually attractive,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures approaching 230°C and above...
• Thanks to the option of flexible molding and customization to individualized projects, magnetic components can be manufactured in a broad palette of forms and dimensions, which amplifies use scope,
• Wide application in advanced technology sectors – they find application in mass storage devices, drive modules, advanced medical instruments, and industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which allows their use in miniature devices

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution protects the magnet and simultaneously increases its durability.
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
• Limited ability of making nuts in the magnet and complex shapes - preferred is casing - mounting mechanism.
• Health risk to health – tiny shards of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child health protection. Furthermore, tiny parts of these devices can be problematic in diagnostics medical in case of swallowing.
• With large orders the cost of neodymium magnets is a challenge,

Magnetic strength at its maximum – what affects it?

The load parameter shown represents the peak performance, measured under laboratory conditions, meaning:

• with the use of a sheet made of special test steel, ensuring maximum field concentration
• with a cross-section minimum 10 mm
• with an ideally smooth contact surface
• without the slightest insulating layer between the magnet and steel
• for force acting at a right angle (in the magnet axis)
• in temp. approx. 20°C

Impact of factors on magnetic holding capacity in practice

It is worth knowing that the application force will differ depending on elements below, starting with the most relevant:

• Space between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Base massiveness – insufficiently thick steel does not close the flux, causing part of the power to be escaped into the air.
• Chemical composition of the base – low-carbon steel gives the best results. Alloy steels decrease magnetic permeability and lifting capacity.
• Plate texture – smooth surfaces ensure maximum contact, which increases field saturation. Rough surfaces reduce efficiency.
• Temperature influence – hot environment weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity was determined using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 5 times. Moreover, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.