SM 32x225 [2xM8] / N52 - magnetic separator

Strengths as well as weaknesses of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• Their power remains stable, and after approximately 10 years it decreases only by ~1% (theoretically),
• They are noted for resistance to demagnetization induced by external disturbances,
• Thanks to the elegant finish, the surface of Ni-Cu-Ni, gold, or silver-plated gives an modern appearance,
• Magnetic induction on the working layer of the magnet turns out to be maximum,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Thanks to flexibility in forming and the capacity to adapt to individual projects,
• Key role in modern industrial fields – they are used in HDD drives, brushless drives, advanced medical instruments, as well as technologically advanced constructions.
• Thanks to efficiency per cm³, small magnets offer high operating force, in miniature format,

Disadvantages of NdFeB magnets:

• At very strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets decrease their power 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• Due to limitations in realizing nuts and complex forms in magnets, we recommend using cover - magnetic mount.
• Potential hazard resulting from small fragments of magnets pose a threat, in case of ingestion, which is particularly important in the context of child safety. Furthermore, small components of these magnets are able to be problematic in diagnostics 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

Highest magnetic holding force – what it depends on?

Holding force of 0 kg is a measurement result performed under specific, ideal conditions:

• on a base made of structural steel, optimally conducting the magnetic field
• possessing a massiveness of minimum 10 mm to ensure full flux closure
• with an ideally smooth contact surface
• without the slightest air gap between the magnet and steel
• for force applied at a right angle (pull-off, not shear)
• at ambient temperature approx. 20 degrees Celsius

Key elements affecting lifting force

In real-world applications, the real power depends on a number of factors, presented from crucial:

• Air gap (betwixt the magnet and the metal), as even a microscopic distance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to paint, rust or dirt).
• Loading method – declared lifting capacity refers to detachment vertically. When slipping, the magnet holds much less (often approx. 20-30% of maximum force).
• Substrate thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Metal type – not every steel reacts the same. High carbon content weaken the interaction with the magnet.
• Plate texture – smooth surfaces guarantee perfect abutment, which improves field saturation. Uneven metal weaken the grip.
• Thermal factor – high temperature reduces magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity was determined with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, in contrast under shearing force the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.