MW 80x30 / N38 - cylindrical magnet

Pros as well as cons of rare earth magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They retain magnetic properties for around ten years – the loss is just ~1% (according to analyses),
• They are resistant to demagnetization induced by external magnetic fields,
• Thanks to the reflective finish, the coating of nickel, gold-plated, or silver gives an elegant appearance,
• They are known for high magnetic induction at the operating surface, which increases their power,
• 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...
• Possibility of detailed forming as well as adjusting to complex needs,
• Versatile presence in electronics industry – they are used in mass storage devices, motor assemblies, medical devices, and modern systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which enables their usage in small systems

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• 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, when using outdoors
• We suggest casing - magnetic holder, due to difficulties in creating nuts inside the magnet and complex forms.
• Possible danger resulting from small fragments of magnets can be dangerous, if swallowed, which becomes key in the context of child safety. It is also worth noting that small components of these magnets can disrupt the diagnostic process medical when they are in the body.
• With budget limitations the cost of neodymium magnets is economically unviable,

Breakaway strength of the magnet in ideal conditions – what affects it?

Holding force of 132.7 kg is a result of laboratory testing performed under the following configuration:

• on a base made of mild steel, perfectly concentrating the magnetic field
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with an ground contact surface
• without the slightest air gap between the magnet and steel
• under axial application of breakaway force (90-degree angle)
• at temperature room level

Magnet lifting force in use – key factors

Effective lifting capacity is affected by specific conditions, mainly (from priority):

• Gap between surfaces – every millimeter of distance (caused e.g. by varnish or unevenness) drastically reduces the pulling force, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to detachment vertically. When applying parallel force, the magnet holds much less (typically approx. 20-30% of maximum force).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Steel grade – the best choice is pure iron steel. Cast iron may generate lower lifting capacity.
• Surface structure – the more even the surface, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
• Temperature – temperature increase causes a temporary drop of force. Check the maximum operating temperature for a given model.

* Lifting capacity was determined with the use of a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular detachment force, in contrast under shearing force the load capacity is reduced by as much as fivefold. In addition, even a minimal clearance {between} the magnet’s surface and the plate lowers the lifting capacity.