MW 9x3 / N38 - cylindrical magnet

Pros as well as cons of rare earth magnets.

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

• They retain attractive force for almost 10 years – the drop is just ~1% (according to analyses),
• They are noted for resistance to demagnetization induced by external field influence,
• In other words, due to the metallic surface of gold, the element becomes visually attractive,
• Magnetic induction on the working layer of the magnet is strong,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Thanks to modularity in forming and the ability to modify to unusual requirements,
• Wide application in electronics industry – they are used in computer drives, electromotive mechanisms, precision medical tools, also complex engineering applications.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Problematic aspects of neodymium magnets: tips and applications.

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also improves its resistance to damage
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• They rust in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Limited possibility of producing nuts in the magnet and complex forms - recommended is cover - mounting mechanism.
• Potential hazard resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which gains importance in the aspect of protecting the youngest. Furthermore, small components of these products can disrupt the diagnostic process medical in case of swallowing.
• With large orders the cost of neodymium magnets is economically unviable,

Optimal lifting capacity of a neodymium magnet – what affects it?

Information about lifting capacity was defined for the most favorable conditions, including:

• using a base made of mild steel, functioning as a ideal flux conductor
• whose thickness reaches at least 10 mm
• with a plane perfectly flat
• with total lack of distance (without coatings)
• for force applied at a right angle (in the magnet axis)
• at standard ambient temperature

What influences lifting capacity in practice

In real-world applications, the actual lifting capacity is determined by many variables, listed from the most important:

• Distance – existence of any layer (paint, tape, gap) interrupts the magnetic circuit, which lowers capacity steeply (even by 50% at 0.5 mm).
• Force direction – note that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Material type – ideal substrate is pure iron steel. Hardened steels may have worse magnetic properties.
• Surface condition – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces weaken the grip.
• Thermal environment – heating the magnet causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was measured on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet and the plate decreases the lifting capacity.