UMH 32x8x46 [M6] / N38 - magnetic holder with hook

Strengths and weaknesses of rare earth magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They retain attractive force for around 10 years – the drop is just ~1% (based on simulations),
• They have excellent resistance to magnetic field loss as a result of external magnetic sources,
• By applying a decorative coating of nickel, the element has an professional look,
• The surface of neodymium magnets generates a intense magnetic field – this is one of their assets,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to freedom in constructing and the ability to modify to individual projects,
• Versatile presence in future technologies – they find application in computer drives, drive modules, diagnostic systems, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which allows their use in miniature devices

Cons of neodymium magnets: tips and applications.

• At strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets decrease their force 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
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
• We recommend casing - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complex shapes.
• Possible danger related to microscopic parts of magnets are risky, if swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that tiny parts of these devices are able to be problematic in diagnostics medical after entering the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which can limit application in large quantities

Highest magnetic holding force – what affects it?

The lifting capacity listed is a result of laboratory testing performed under the following configuration:

• with the application of a yoke made of special test steel, ensuring full magnetic saturation
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with a surface free of scratches
• without the slightest insulating layer between the magnet and steel
• under axial application of breakaway force (90-degree angle)
• in neutral thermal conditions

Practical lifting capacity: influencing factors

During everyday use, the actual lifting capacity is determined by several key aspects, ranked from the most important:

• Clearance – the presence of foreign body (paint, tape, gap) acts as an insulator, which reduces capacity steeply (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet exhibits much less (often approx. 20-30% of nominal force).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Metal type – not every steel reacts the same. High carbon content worsen the attraction effect.
• Surface structure – the more even the plate, the larger the contact zone and stronger the hold. Roughness acts like micro-gaps.
• Temperature influence – high temperature weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was performed on plates with a smooth surface of suitable thickness, under perpendicular forces, in contrast under shearing force the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the load capacity.