MW 8x5 / N38 - cylindrical magnet

Pros as well as cons of neodymium magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They do not lose power, even during nearly 10 years – the reduction in power is only ~1% (based on measurements),
• They have excellent resistance to magnetism drop when exposed to external fields,
• A magnet with a shiny gold surface looks better,
• Magnetic induction on the surface of the magnet turns out to be strong,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• Possibility of detailed forming and adjusting to atypical requirements,
• Significant place in electronics industry – they are commonly used in mass storage devices, electric drive systems, medical devices, also technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only protects the magnet but also improves its resistance to damage
• 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 and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation and corrosion.
• Limited possibility of creating threads in the magnet and complicated forms - recommended is casing - magnetic holder.
• Health risk to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the context of child safety. Furthermore, small elements of these devices can be problematic in diagnostics medical after entering the body.
• Due to complex production process, their price is relatively high,

Best holding force of the magnet in ideal parameters – what contributes to it?

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

• using a sheet made of mild steel, functioning as a circuit closing element
• with a thickness minimum 10 mm
• with an ground contact surface
• without the slightest insulating layer between the magnet and steel
• during pulling in a direction vertical to the plane
• at room temperature

Impact of factors on magnetic holding capacity in practice

In real-world applications, the actual holding force depends on many variables, ranked from the most important:

• Clearance – existence of any layer (paint, tape, air) interrupts the magnetic circuit, which lowers power rapidly (even by 50% at 0.5 mm).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Base massiveness – too thin sheet does not close the flux, causing part of the power to be wasted into the air.
• Plate material – low-carbon steel attracts best. Alloy admixtures reduce magnetic properties and lifting capacity.
• Smoothness – full contact is obtained only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Thermal factor – high temperature weakens pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was determined by applying a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under shearing force the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate reduces the lifting capacity.