MW 8x10 / N38 - cylindrical magnet

Strengths and weaknesses of neodymium magnets.

Besides their immense strength, neodymium magnets offer the following advantages:

• Their strength is maintained, and after around 10 years it drops only by ~1% (according to research),
• Neodymium magnets prove to be extremely resistant to loss of magnetic properties caused by external field sources,
• A magnet with a metallic gold surface is more attractive,
• They show high magnetic induction at the operating surface, which improves attraction properties,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to freedom in constructing and the capacity to adapt to specific needs,
• Versatile presence in modern industrial fields – they are commonly used in HDD drives, electromotive mechanisms, medical devices, as well as other advanced devices.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only shields the magnet but also improves its resistance to damage
• Neodymium magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening 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 very resistant to heat
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Limited ability of making nuts in the magnet and complex shapes - preferred is casing - magnetic holder.
• Potential hazard resulting from small fragments of magnets are risky, in case of ingestion, which is particularly important in the context of child health protection. Furthermore, small elements of these magnets are able to complicate diagnosis medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Highest magnetic holding force – what contributes to it?

The load parameter shown represents the peak performance, recorded under optimal environment, namely:

• using a plate made of mild steel, acting as a ideal flux conductor
• whose transverse dimension reaches at least 10 mm
• with an ground touching surface
• with zero gap (without paint)
• during detachment in a direction vertical to the mounting surface
• at ambient temperature room level

Lifting capacity in real conditions – factors

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

• Clearance – the presence of any layer (paint, tape, gap) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Force direction – catalog parameter refers to pulling vertically. When slipping, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Base massiveness – too thin sheet causes magnetic saturation, causing part of the power to be escaped to the other side.
• Material type – the best choice is high-permeability steel. Cast iron may have worse magnetic properties.
• Surface condition – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces reduce efficiency.
• Thermal environment – temperature increase causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under perpendicular forces, however under parallel forces the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet and the plate lowers the holding force.