MW 6x6 / N38 - cylindrical magnet

Pros and cons of rare earth magnets.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They retain attractive force for almost ten years – the loss is just ~1% (based on simulations),
• They have excellent resistance to magnetic field loss due to opposing magnetic fields,
• In other words, due to the shiny surface of silver, the element is aesthetically pleasing,
• They feature high magnetic induction at the operating surface, which increases their power,
• Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of accurate machining as well as modifying to concrete applications,
• Key role in modern industrial fields – they serve a role in hard drives, motor assemblies, medical devices, and multitasking production systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a steel housing, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets experience a drop in strength. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We recommend cover - magnetic mechanism, due to difficulties in creating threads inside the magnet and complicated forms.
• Potential hazard to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the context of child safety. It is also worth noting that tiny parts of these products can complicate diagnosis medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

Detachment force of the magnet in optimal conditions – what affects it?

Breakaway force was defined for optimal configuration, taking into account:

• using a sheet made of mild steel, serving as a circuit closing element
• possessing a massiveness of at least 10 mm to avoid saturation
• characterized by lack of roughness
• without any air gap between the magnet and steel
• for force applied at a right angle (in the magnet axis)
• at temperature approx. 20 degrees Celsius

Practical lifting capacity: influencing factors

In practice, the actual holding force is determined by several key aspects, presented from most significant:

• Gap between magnet and steel – every millimeter of distance (caused e.g. by varnish or dirt) diminishes the pulling force, often by half at just 0.5 mm.
• Loading method – catalog parameter refers to detachment vertically. When slipping, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Material type – ideal substrate is pure iron steel. Cast iron may have worse magnetic properties.
• Base smoothness – the smoother and more polished the plate, the better the adhesion and stronger the hold. Roughness acts like micro-gaps.
• Thermal factor – high temperature reduces pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was performed on a smooth plate of suitable thickness, under perpendicular forces, whereas under shearing force the load capacity is reduced by as much as fivefold. Moreover, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.