MW 10x10 / N38 - cylindrical magnet

Pros as well as cons of neodymium magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• They have excellent resistance to weakening of magnetic properties when exposed to external fields,
• By covering with a lustrous coating of silver, the element presents an proper look,
• They are known for high magnetic induction at the operating surface, which increases their power,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of exact machining as well as adjusting to complex requirements,
• Universal use in modern technologies – they serve a role in data components, drive modules, precision medical tools, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which makes them useful in compact constructions

Problematic aspects of neodymium magnets: weaknesses and usage proposals

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a steel housing, which not only secures them against impacts but also raises their durability
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture, in case of application outdoors
• Limited ability of producing threads in the magnet and complicated forms - recommended is casing - magnetic holder.
• Health risk to health – tiny shards of magnets pose a threat, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that small elements of these devices can disrupt the diagnostic process medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what contributes to it?

Magnet power was determined for the most favorable conditions, assuming:

• with the contact of a sheet made of special test steel, guaranteeing full magnetic saturation
• whose transverse dimension equals approx. 10 mm
• with an ground contact surface
• without any air gap between the magnet and steel
• during detachment in a direction perpendicular to the mounting surface
• in stable room temperature

Determinants of practical lifting force of a magnet

Please note that the application force will differ depending on the following factors, in order of importance:

• Distance – the presence of any layer (paint, dirt, gap) interrupts the magnetic circuit, which reduces capacity steeply (even by 50% at 0.5 mm).
• Angle of force application – maximum parameter is reached only during pulling at a 90° angle. The force required to slide of the magnet along the surface is usually several times smaller (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Metal type – different alloys reacts the same. High carbon content worsen the attraction effect.
• Surface quality – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Unevenness creates an air distance.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures 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 perpendicular forces, in contrast under shearing force the holding force is lower. In addition, even a small distance {between} the magnet and the plate reduces the lifting capacity.