SM 32x275 [2xM8] / N42 - magnetic separator

Strengths and weaknesses of NdFeB magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• Their magnetic field is durable, and after approximately 10 years it decreases only by ~1% (theoretically),
• They maintain their magnetic properties even under close interference source,
• A magnet with a metallic gold surface has an effective appearance,
• The surface of neodymium magnets generates a maximum magnetic field – this is one of their assets,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to the potential of accurate molding and adaptation to unique requirements, NdFeB magnets can be created in a wide range of forms and dimensions, which increases their versatility,
• Versatile presence in electronics industry – they find application in data components, electric motors, medical devices, and multitasking production systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

What to avoid - cons of neodymium magnets: application proposals

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets lose their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Limited ability of producing nuts in the magnet and complex forms - preferred is a housing - mounting mechanism.
• Potential hazard resulting from small fragments of magnets are risky, if swallowed, which gains importance in the aspect of protecting the youngest. Additionally, small elements of these devices are able to be problematic in diagnostics medical after entering the body.
• Due to complex production process, their price is relatively high,

Maximum magnetic pulling force – what contributes to it?

The load parameter shown represents the peak performance, recorded under ideal test conditions, meaning:

• on a base made of mild steel, effectively closing the magnetic field
• whose thickness reaches at least 10 mm
• with an ideally smooth contact surface
• with total lack of distance (without coatings)
• for force acting at a right angle (in the magnet axis)
• at room temperature

Determinants of practical lifting force of a magnet

During everyday use, the actual lifting capacity depends on many variables, presented from the most important:

• Air gap (betwixt the magnet and the plate), as even a very small distance (e.g. 0.5 mm) can cause a drastic drop in force by up to 50% (this also applies to varnish, corrosion or dirt).
• Force direction – remember that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Steel grade – ideal substrate is high-permeability steel. Hardened steels may attract less.
• Plate texture – ground elements guarantee perfect abutment, which improves field saturation. Uneven metal weaken the grip.
• Heat – neodymium magnets have a sensitivity to temperature. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity testing was performed on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, whereas under parallel forces the holding force is lower. Additionally, even a minimal clearance {between} the magnet’s surface and the plate lowers the holding force.