MW 16x9 / N38 - cylindrical magnet

Pros and cons of rare earth magnets.

Apart from their strong power, neodymium magnets have these key benefits:

• Their strength is durable, and after approximately 10 years it drops only by ~1% (according to research),
• They have excellent resistance to weakening of magnetic properties due to external magnetic sources,
• By covering with a decorative layer of silver, the element gains an elegant look,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling functioning at temperatures approaching 230°C and above...
• Thanks to flexibility in constructing and the ability to customize to unusual requirements,
• Universal use in modern technologies – they are used in computer drives, brushless drives, precision medical tools, as well as modern systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which enables their usage in miniature devices

What to avoid - cons of neodymium magnets: application proposals

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets decrease 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 durability even at temperatures up to 230°C
• They oxidize in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Due to limitations in producing threads and complex shapes in magnets, we recommend using a housing - magnetic holder.
• Health risk resulting from small fragments of magnets pose a threat, if swallowed, which gains importance in the context of child health protection. Additionally, small components of these products can disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Magnetic strength at its maximum – what contributes to it?

The load parameter shown refers to the peak performance, measured under laboratory conditions, meaning:

• with the contact of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• with a thickness of at least 10 mm
• characterized by even structure
• with zero gap (no paint)
• during pulling in a direction perpendicular to the plane
• at temperature room level

Lifting capacity in real conditions – factors

It is worth knowing that the application force will differ depending on the following factors, starting with the most relevant:

• Clearance – the presence of foreign body (paint, dirt, gap) acts as an insulator, which reduces power rapidly (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to detachment vertically. When applying parallel force, the magnet holds much less (often approx. 20-30% of nominal force).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet limits the attraction force (the magnet "punches through" it).
• Steel grade – the best choice is high-permeability steel. Hardened steels may generate lower lifting capacity.
• Surface finish – ideal contact is obtained only on polished steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal environment – temperature increase causes a temporary drop of induction. Check the thermal limit for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the holding force is lower. Moreover, even a minimal clearance {between} the magnet’s surface and the plate reduces the holding force.