MPL 40x10x5 / N38 - lamellar magnet

Strengths and weaknesses of neodymium magnets.

Apart from their notable magnetic energy, neodymium magnets have these key benefits:

• They do not lose power, even during approximately 10 years – the drop in power is only ~1% (according to tests),
• They show high resistance to demagnetization induced by external magnetic fields,
• Thanks to the reflective finish, the surface of Ni-Cu-Ni, gold-plated, or silver gives an professional appearance,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Thanks to freedom in shaping and the ability to adapt to unusual requirements,
• Wide application in high-tech industry – they serve a role in HDD drives, electromotive mechanisms, medical devices, and multitasking production systems.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Cons of neodymium magnets: weaknesses and usage proposals

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also improves its resistance to damage
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• 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, in case of application outdoors
• Due to limitations in creating threads and complicated shapes in magnets, we recommend using casing - magnetic mechanism.
• Potential hazard to health – tiny shards of magnets can be dangerous, if swallowed, which becomes key in the aspect of protecting the youngest. Additionally, small elements of these devices can disrupt the diagnostic process medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what it depends on?

The load parameter shown concerns the maximum value, recorded under ideal test conditions, namely:

• with the application of a yoke made of special test steel, ensuring maximum field concentration
• whose thickness is min. 10 mm
• with an ideally smooth touching surface
• without any air gap between the magnet and steel
• for force acting at a right angle (in the magnet axis)
• at room temperature

What influences lifting capacity in practice

It is worth knowing that the application force may be lower subject to the following factors, starting with the most relevant:

• Clearance – the presence of any layer (rust, dirt, gap) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Angle of force application – highest force is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet limits the attraction force (the magnet "punches through" it).
• Plate material – mild steel gives the best results. Higher carbon content reduce magnetic properties and lifting capacity.
• Surface finish – ideal contact is obtained only on polished steel. Any scratches and bumps create air cushions, weakening the magnet.
• Temperature influence – 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 pulling force, in contrast under shearing force the load capacity is reduced by as much as fivefold. Additionally, even a small distance {between} the magnet and the plate lowers the lifting capacity.