MPL 10x10x3 / N38 - lamellar magnet

Advantages as well as disadvantages of neodymium magnets.

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

• Their strength is maintained, and after around 10 years it drops only by ~1% (according to research),
• They have excellent resistance to weakening of magnetic properties when exposed to external magnetic sources,
• A magnet with a smooth gold surface has better aesthetics,
• They show high magnetic induction at the operating surface, which improves attraction properties,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and are able to act (depending on the form) even at a temperature of 230°C or more...
• Thanks to freedom in forming and the ability to modify to individual projects,
• Huge importance in innovative solutions – they serve a role in HDD drives, electric drive systems, diagnostic systems, and technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer high power in compact dimensions, which enables their usage in small systems

Disadvantages of neodymium magnets:

• At strong impacts they can crack, therefore we recommend placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation as well as corrosion.
• Due to limitations in producing nuts and complicated forms in magnets, we propose using a housing - magnetic holder.
• Possible danger resulting from small fragments of magnets are risky, if swallowed, which is particularly important in the context of child safety. Additionally, small elements of these products can be problematic in diagnostics medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which hinders application in large quantities

Highest magnetic holding force – what affects it?

Holding force of 2.37 kg is a theoretical maximum value executed under standard conditions:

• using a plate made of low-carbon steel, serving as a circuit closing element
• whose thickness is min. 10 mm
• with an ground touching surface
• under conditions of no distance (surface-to-surface)
• for force applied at a right angle (pull-off, not shear)
• in temp. approx. 20°C

Magnet lifting force in use – key factors

Real force impacted by specific conditions, such as (from priority):

• Gap between magnet and steel – every millimeter of distance (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – maximum parameter is obtained only during pulling at a 90° angle. The shear force of the magnet along the plate is usually several times smaller (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 grade – ideal substrate is pure iron steel. Hardened steels may attract less.
• Surface quality – the more even the surface, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Heat – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was measured by applying a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under parallel forces the load capacity is reduced by as much as 75%. Additionally, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.