MPL 25x2x6 / N38 - lamellar magnet

Advantages as well as disadvantages of rare earth magnets.

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

• They do not lose power, even after around ten years – the drop in lifting capacity is only ~1% (according to tests),
• They maintain their magnetic properties even under close interference source,
• A magnet with a smooth gold surface looks better,
• Magnetic induction on the top side of the magnet remains very high,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• In view of the possibility of precise shaping and adaptation to specialized needs, magnetic components can be manufactured in a broad palette of geometric configurations, which increases their versatility,
• Universal use in modern technologies – they serve a role in hard drives, electric drive systems, medical equipment, and multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which allows their use in compact constructions

Disadvantages of neodymium magnets:

• To avoid cracks under impact, 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.
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• Limited possibility of creating nuts in the magnet and complex forms - recommended is cover - magnetic holder.
• Possible danger related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the context of child health protection. Additionally, small elements of these products can be problematic in diagnostics medical when they are in the body.
• Due to neodymium price, their price exceeds standard values,

Optimal lifting capacity of a neodymium magnet – what it depends on?

The declared magnet strength refers to the limit force, obtained under ideal test conditions, specifically:

• with the use of a sheet made of special test steel, ensuring maximum field concentration
• possessing a massiveness of minimum 10 mm to avoid saturation
• with a surface perfectly flat
• with direct contact (no coatings)
• under vertical application of breakaway force (90-degree angle)
• in stable room temperature

Lifting capacity in real conditions – factors

Holding efficiency is influenced by working environment parameters, such as (from priority):

• Space between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) diminishes the pulling force, often by half at just 0.5 mm.
• Load vector – maximum parameter is obtained only during pulling at a 90° angle. The force required to slide of the magnet along the plate is standardly many times smaller (approx. 1/5 of the lifting capacity).
• Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of generating force.
• Material type – ideal substrate is high-permeability steel. Hardened steels may have worse magnetic properties.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Uneven metal reduce efficiency.
• Temperature – temperature increase results in weakening of induction. Check the maximum operating temperature for a given model.

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under a perpendicular pulling force, however under shearing force the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet and the plate decreases the holding force.