SMZR 32x225 / N52 - magnetic separator with handle

Advantages and disadvantages of neodymium magnets.

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

• They virtually do not lose power, because even after 10 years the decline in efficiency is only ~1% (in laboratory conditions),
• Magnets effectively resist against demagnetization caused by ambient magnetic noise,
• In other words, due to the smooth finish of gold, the element gains a professional look,
• Neodymium magnets ensure maximum magnetic induction on a contact point, which increases force concentration,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Thanks to versatility in constructing and the capacity to modify to individual projects,
• Fundamental importance in modern industrial fields – they are commonly used in data components, electric motors, medical equipment, as well as other advanced devices.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets and ways of using them

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape as well as 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
• 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.
• Due to limitations in realizing nuts and complex shapes in magnets, we propose using casing - magnetic mechanism.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child safety. It is also worth noting that tiny parts of these magnets can be problematic in diagnostics medical after entering the body.
• Due to expensive raw materials, their price exceeds standard values,

Maximum magnetic pulling force – what affects it?

Breakaway force was determined for the most favorable conditions, assuming:

• with the application of a yoke made of special test steel, ensuring full magnetic saturation
• possessing a massiveness of at least 10 mm to ensure full flux closure
• characterized by smoothness
• with zero gap (without paint)
• under vertical application of breakaway force (90-degree angle)
• at temperature approx. 20 degrees Celsius

What influences lifting capacity in practice

Effective lifting capacity impacted by working environment parameters, such as (from most important):

• Gap (betwixt the magnet and the metal), because even a microscopic distance (e.g. 0.5 mm) results in a decrease in lifting capacity by up to 50% (this also applies to paint, rust or dirt).
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of generating force.
• Metal type – different alloys attracts identically. High carbon content worsen the attraction effect.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Rough surfaces weaken the grip.
• Heat – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was measured with the use of a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under shearing force the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet’s surface and the plate lowers the lifting capacity.