SM 25x175 [2xM8] / N52 - magnetic separator

Pros as well as cons of NdFeB magnets.

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

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (based on calculations),
• Magnets effectively resist against loss of magnetization caused by ambient magnetic noise,
• A magnet with a smooth nickel surface looks better,
• Neodymium magnets deliver maximum magnetic induction on a contact point, which ensures high operational effectiveness,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for operation at temperatures approaching 230°C and above...
• Possibility of precise forming and adapting to concrete needs,
• Universal use in high-tech industry – they serve a role in computer drives, brushless drives, medical equipment, also modern systems.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Cons of neodymium magnets: application proposals

• They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• They oxidize in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic holder, due to difficulties in producing threads inside the magnet and complex forms.
• Health risk related to microscopic parts of magnets pose a threat, when accidentally swallowed, which gains importance in the aspect of protecting the youngest. Furthermore, small elements of these devices can be problematic in diagnostics medical when they are in the body.
• Due to expensive raw materials, their price is relatively high,

Magnetic strength at its maximum – what it depends on?

The specified lifting capacity refers to the maximum value, recorded under optimal environment, meaning:

• with the application of a sheet made of special test steel, guaranteeing maximum field concentration
• possessing a massiveness of minimum 10 mm to avoid saturation
• with an polished touching surface
• without the slightest insulating layer between the magnet and steel
• during detachment in a direction vertical to the mounting surface
• at ambient temperature approx. 20 degrees Celsius

Key elements affecting lifting force

It is worth knowing that the working load will differ subject to the following factors, in order of importance:

• Distance – the presence of foreign body (paint, tape, air) acts as an insulator, which reduces power rapidly (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to pulling vertically. When slipping, the magnet holds much less (often approx. 20-30% of nominal force).
• Base massiveness – insufficiently thick plate does not close the flux, causing part of the power to be escaped into the air.
• Chemical composition of the base – low-carbon steel attracts best. Alloy admixtures lower magnetic permeability and lifting capacity.
• Plate texture – ground elements guarantee perfect abutment, which increases force. Rough surfaces weaken the grip.
• Thermal environment – heating the magnet results in weakening of force. It is worth remembering the thermal limit for a given model.

* Holding force was checked on the plate surface of 20 mm thickness, when the force acted perpendicularly, whereas under parallel forces the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet and the plate lowers the holding force.