SM 25x150 [2xM8] / N42 - magnetic separator

Pros and cons of neodymium magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They have unchanged lifting capacity, and over more than 10 years their performance decreases symbolically – ~1% (in testing),
• They feature excellent resistance to weakening of magnetic properties when exposed to external fields,
• Thanks to the elegant finish, the surface of nickel, gold, or silver gives an visually attractive appearance,
• Magnets possess impressive magnetic induction on the active area,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Due to the possibility of precise shaping and customization to unique needs, neodymium magnets can be created in a wide range of forms and dimensions, which makes them more universal,
• Wide application in innovative solutions – they find application in HDD drives, brushless drives, precision medical tools, also complex engineering applications.
• Thanks to their power density, small magnets offer high operating force, in miniature format,

Disadvantages of neodymium magnets:

• To avoid cracks under impact, we suggest using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
• When exposed to high temperature, neodymium magnets suffer a drop in strength. 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 those in rubber or plastics, which prevent oxidation and corrosion.
• Due to limitations in producing nuts and complicated forms in magnets, we propose using casing - magnetic mechanism.
• Potential hazard resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which becomes key in the context of child health protection. Additionally, small components of these magnets are able to be problematic in diagnostics medical after entering the body.
• With mass production the cost of neodymium magnets can be a barrier,

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

Magnet power is the result of a measurement for ideal contact conditions, taking into account:

• on a base made of structural steel, effectively closing the magnetic flux
• whose transverse dimension is min. 10 mm
• with an ideally smooth contact surface
• under conditions of ideal adhesion (metal-to-metal)
• under perpendicular force vector (90-degree angle)
• at room temperature

Practical aspects of lifting capacity – factors

During everyday use, the actual holding force is determined by several key aspects, listed from crucial:

• Distance – the presence of any layer (paint, dirt, air) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Force direction – catalog parameter refers to pulling vertically. When applying parallel force, the magnet exhibits much less (typically approx. 20-30% of nominal force).
• Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Material composition – different alloys attracts identically. High carbon content worsen the attraction effect.
• Plate texture – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces weaken the grip.
• Heat – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and in frost gain strength (up to a certain limit).

* Lifting capacity was determined using a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, however under parallel forces the lifting capacity is smaller. In addition, even a slight gap {between} the magnet and the plate reduces the load capacity.