MW 14x10 / N38 - cylindrical magnet

Advantages and disadvantages of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They do not lose strength, even after nearly 10 years – the reduction in power is only ~1% (according to tests),
• They show high resistance to demagnetization induced by external disturbances,
• Thanks to the shiny finish, the surface of Ni-Cu-Ni, gold-plated, or silver gives an clean appearance,
• Neodymium magnets ensure maximum magnetic induction on a contact point, which allows for strong attraction,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• In view of the potential of accurate forming and adaptation to unique needs, NdFeB magnets can be created in a broad palette of geometric configurations, which makes them more universal,
• Versatile presence in high-tech industry – they are used in hard drives, electric motors, medical devices, and other advanced devices.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Limited ability of making nuts in the magnet and complex forms - preferred is a housing - magnetic holder.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which gains importance in the context of child safety. Additionally, small elements of these magnets are able to complicate diagnosis medical in case of swallowing.
• With mass production the cost of neodymium magnets is a challenge,

Breakaway strength of the magnet in ideal conditions – what affects it?

Magnet power was defined for optimal configuration, assuming:

• on a block made of mild steel, effectively closing the magnetic flux
• whose thickness reaches at least 10 mm
• with a plane cleaned and smooth
• with direct contact (without impurities)
• for force acting at a right angle (in the magnet axis)
• at conditions approx. 20°C

Lifting capacity in practice – influencing factors

In practice, the actual lifting capacity is determined by many variables, listed from crucial:

• Gap (between the magnet and the metal), because even a microscopic clearance (e.g. 0.5 mm) leads to a decrease in lifting capacity by up to 50% (this also applies to paint, corrosion or dirt).
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Steel thickness – too thin plate causes magnetic saturation, causing part of the power to be escaped into the air.
• Steel grade – ideal substrate is pure iron steel. Cast iron may have worse magnetic properties.
• Base smoothness – the smoother and more polished the surface, the better the adhesion and higher the lifting capacity. Roughness acts like micro-gaps.
• Thermal environment – temperature increase results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity testing was performed on a smooth plate of suitable thickness, under a perpendicular pulling force, whereas under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate decreases the load capacity.