MW 14x10 / N38 - cylindrical magnet

Pros as well as cons of rare earth magnets.

Apart from their notable holding force, neodymium magnets have these key benefits:

• They do not lose magnetism, even over around 10 years – the reduction in lifting capacity is only ~1% (based on measurements),
• Magnets effectively protect themselves against demagnetization caused by external fields,
• In other words, due to the smooth finish of gold, the element gains visual value,
• They show high magnetic induction at the operating surface, which affects their effectiveness,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Possibility of individual creating and optimizing to defined applications,
• Wide application in modern industrial fields – they find application in hard drives, motor assemblies, diagnostic systems, as well as complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: weaknesses and usage proposals

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a special holder, which not only secures them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We suggest cover - magnetic mechanism, due to difficulties in creating threads inside the magnet and complex forms.
• Health risk to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that tiny parts of these magnets are able to 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

Highest magnetic holding force – what it depends on?

The load parameter shown concerns the maximum value, measured under optimal environment, meaning:

• on a block made of mild steel, optimally conducting the magnetic flux
• with a cross-section minimum 10 mm
• with an ideally smooth contact surface
• under conditions of gap-free contact (surface-to-surface)
• during detachment in a direction vertical to the mounting surface
• in temp. approx. 20°C

Determinants of practical lifting force of a magnet

During everyday use, the actual holding force is determined by many variables, listed from crucial:

• Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to pulling vertically. When attempting to slide, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Steel thickness – insufficiently thick sheet does not close the flux, causing part of the power to be lost into the air.
• Material composition – not every steel attracts identically. High carbon content worsen the interaction with the magnet.
• Base smoothness – the more even the plate, the better the adhesion and stronger the hold. Roughness acts like micro-gaps.
• Temperature influence – high temperature weakens pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the lifting capacity is smaller. In addition, even a small distance {between} the magnet and the plate decreases the lifting capacity.