MW 6x2 / N38 - cylindrical magnet

Strengths and weaknesses of NdFeB magnets.

Besides their immense magnetic power, neodymium magnets offer the following advantages:

• They retain magnetic properties for almost 10 years – the drop is just ~1% (in theory),
• Neodymium magnets are characterized by extremely resistant to magnetic field loss caused by external interference,
• By using a shiny coating of silver, the element presents an nice look,
• Neodymium magnets ensure maximum magnetic induction on a contact point, which ensures high operational effectiveness,
• 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 versatility in designing and the ability to modify to client solutions,
• Key role in modern technologies – they are used in hard drives, motor assemblies, medical devices, also other advanced devices.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

What to avoid - cons of neodymium magnets and proposals for their use:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only protects the magnet but also improves its resistance to damage
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• Due to limitations in creating nuts and complicated forms in magnets, we recommend using casing - magnetic mechanism.
• Possible danger to health – tiny shards of magnets can be dangerous, if swallowed, which becomes key in the context of child health protection. Additionally, small elements 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 increases costs of application in large quantities

Maximum magnetic pulling force – what it depends on?

Holding force of 0.66 kg is a result of laboratory testing performed under standard conditions:

• with the application of a sheet made of low-carbon steel, ensuring full magnetic saturation
• with a cross-section no less than 10 mm
• with a plane cleaned and smooth
• without any insulating layer between the magnet and steel
• during pulling in a direction vertical to the mounting surface
• at ambient temperature room level

Determinants of lifting force in real conditions

During everyday use, the real power is determined by many variables, listed from most significant:

• Air gap (between the magnet and the metal), as even a very small clearance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to paint, rust or dirt).
• Angle of force application – highest force is obtained only during perpendicular pulling. The shear force of the magnet along the surface is standardly many times lower (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Steel type – mild steel attracts best. Alloy admixtures lower magnetic permeability and lifting capacity.
• Plate texture – smooth surfaces ensure maximum contact, which improves field saturation. Uneven metal reduce efficiency.
• Thermal environment – temperature increase results in weakening of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was determined by applying a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the holding force is lower. Additionally, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.