SM 32x375 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of rare earth magnets.

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

• They retain full power for almost 10 years – the loss is just ~1% (based on simulations),
• They possess excellent resistance to magnetic field loss as a result of opposing magnetic fields,
• In other words, due to the metallic finish of silver, the element becomes visually attractive,
• Magnets are distinguished by excellent magnetic induction on the working surface,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures reaching 230°C and above...
• Possibility of detailed forming and adapting to concrete requirements,
• Wide application in modern technologies – they are commonly used in magnetic memories, drive modules, 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:

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• NdFeB magnets lose force 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
• They rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in creating nuts and complex forms in magnets, we propose using cover - magnetic mount.
• Health risk related to microscopic parts of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child health protection. Furthermore, small elements of these products are able to be problematic in diagnostics medical after entering the body.
• Due to neodymium price, their price exceeds standard values,

Maximum holding power of the magnet – what affects it?

The lifting capacity listed is a measurement result conducted under standard conditions:

• using a base made of high-permeability steel, functioning as a circuit closing element
• whose transverse dimension is min. 10 mm
• with a plane perfectly flat
• with total lack of distance (without impurities)
• under perpendicular force direction (90-degree angle)
• at room temperature

Practical lifting capacity: influencing factors

Effective lifting capacity is affected by specific conditions, such as (from most important):

• Air gap (betwixt the magnet and the metal), since even a microscopic distance (e.g. 0.5 mm) results in a decrease in lifting capacity by up to 50% (this also applies to varnish, corrosion or dirt).
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Material type – the best choice is pure iron steel. Cast iron may have worse magnetic properties.
• Surface finish – full contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Heat – NdFeB sinters have a negative temperature coefficient. When it is hot they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under perpendicular forces, in contrast under parallel forces the load capacity is reduced by as much as fivefold. Additionally, even a slight gap {between} the magnet and the plate lowers the load capacity.