SM 25x325 [2xM8] / N52 - magnetic separator

Pros and cons of neodymium magnets.

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

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (according to literature),
• They are resistant to demagnetization induced by external magnetic fields,
• A magnet with a metallic nickel surface is more attractive,
• The surface of neodymium magnets generates a powerful magnetic field – this is one of their assets,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling action at temperatures approaching 230°C and above...
• Due to the potential of free forming and customization to individualized projects, magnetic components can be modeled in a broad palette of forms and dimensions, which amplifies use scope,
• Versatile presence in electronics industry – they find application in hard drives, brushless drives, precision medical tools, also modern systems.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Problematic aspects of neodymium magnets: tips and applications.

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a strong case, which not only secures them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• We suggest a housing - magnetic mount, due to difficulties in creating threads inside the magnet and complex shapes.
• Potential hazard resulting from small fragments of magnets are risky, in case of ingestion, which becomes key in the context of child health protection. It is also worth noting that tiny parts of these devices are able to be problematic in diagnostics medical after entering the body.
• Due to expensive raw materials, their price is relatively high,

Highest magnetic holding force – what contributes to it?

Information about lifting capacity was determined for optimal configuration, taking into account:

• using a sheet made of mild steel, functioning as a circuit closing element
• possessing a massiveness of minimum 10 mm to avoid saturation
• with an polished touching surface
• under conditions of no distance (surface-to-surface)
• during detachment in a direction vertical to the mounting surface
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

It is worth knowing that the working load will differ subject to elements below, starting with the most relevant:

• Gap (between the magnet and the plate), because even a tiny clearance (e.g. 0.5 mm) leads to a decrease in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Substrate thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Steel grade – the best choice is pure iron steel. Stainless steels may attract less.
• Surface finish – full contact is obtained only on smooth steel. Any scratches and bumps create air cushions, weakening the magnet.
• Heat – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was determined using a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under shearing force the holding force is lower. Moreover, even a minimal clearance {between} the magnet and the plate lowers the load capacity.