SMZR 25x200 / N52 - magnetic separator with handle

Pros as well as cons of neodymium magnets.

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

• Their magnetic field is maintained, and after approximately 10 years it decreases only by ~1% (according to research),
• Magnets perfectly protect themselves against loss of magnetization caused by external fields,
• In other words, due to the reflective layer of gold, the element becomes visually attractive,
• The surface of neodymium magnets generates a unique magnetic field – this is a key feature,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and are able to act (depending on the form) even at a temperature of 230°C or more...
• Possibility of individual creating as well as modifying to specific requirements,
• Versatile presence in future technologies – they are used in HDD drives, motor assemblies, precision medical tools, also modern systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets and ways of using them

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• Neodymium magnets lose their strength 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 stability even at temperatures up to 230°C
• They rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Limited possibility of creating threads in the magnet and complicated shapes - preferred is cover - magnetic holder.
• Health risk to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child safety. It is also worth noting that tiny parts of these magnets can disrupt the diagnostic process medical after entering the body.
• With mass production the cost of neodymium magnets is a challenge,

Best holding force of the magnet in ideal parameters – what affects it?

The declared magnet strength refers to the peak performance, measured under optimal environment, namely:

• with the use of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a massiveness of at least 10 mm to avoid saturation
• characterized by lack of roughness
• with total lack of distance (no impurities)
• for force applied at a right angle (in the magnet axis)
• at temperature room level

Practical lifting capacity: influencing factors

Effective lifting capacity impacted by specific conditions, mainly (from most important):

• Distance – the presence of any layer (paint, tape, gap) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Force direction – catalog parameter refers to detachment vertically. When applying parallel force, the magnet holds significantly lower power (often approx. 20-30% of maximum force).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Metal type – different alloys reacts the same. High carbon content worsen the interaction with the magnet.
• Surface finish – ideal contact is obtained only on polished steel. Rough texture create air cushions, weakening the magnet.
• Operating temperature – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, whereas under parallel forces the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet’s surface and the plate decreases the holding force.