MPL 40x10x5 / N38 - lamellar magnet

Pros as well as cons of neodymium magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They do not lose magnetism, even during around ten years – the reduction in strength is only ~1% (theoretically),
• They possess excellent resistance to weakening of magnetic properties as a result of opposing magnetic fields,
• In other words, due to the smooth finish of nickel, the element becomes visually attractive,
• Magnetic induction on the working part of the magnet is impressive,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and are able to act (depending on the shape) even at a temperature of 230°C or more...
• Thanks to freedom in shaping and the capacity to modify to complex applications,
• Universal use in electronics industry – they serve a role in mass storage devices, brushless drives, precision medical tools, also technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: weaknesses and usage proposals

• At very strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Limited ability of producing nuts in the magnet and complex shapes - preferred is casing - mounting mechanism.
• Health risk resulting from small fragments of magnets are risky, in case of ingestion, which gains importance in the aspect of protecting the youngest. Additionally, tiny parts of these devices are able to be problematic in diagnostics medical in case of swallowing.
• Due to expensive raw materials, their price is relatively high,

Maximum magnetic pulling force – what it depends on?

The lifting capacity listed is a result of laboratory testing conducted under specific, ideal conditions:

• with the contact of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• with a cross-section no less than 10 mm
• characterized by even structure
• under conditions of no distance (metal-to-metal)
• during detachment in a direction vertical to the plane
• at temperature approx. 20 degrees Celsius

Magnet lifting force in use – key factors

Please note that the magnet holding will differ depending on elements below, in order of importance:

• Space between magnet and steel – every millimeter of separation (caused e.g. by veneer or dirt) diminishes the pulling force, often by half at just 0.5 mm.
• Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Steel thickness – too thin steel does not accept the full field, causing part of the flux to be lost to the other side.
• Material type – the best choice is pure iron steel. Cast iron may have worse magnetic properties.
• Base smoothness – the more even the plate, the larger the contact zone and stronger the hold. Roughness acts like micro-gaps.
• Temperature – heating the magnet causes a temporary drop of induction. Check the thermal limit for a given model.

* Lifting capacity was determined with the use of a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet’s surface and the plate lowers the lifting capacity.