MPL 40x18x10 SH / N38 - lamellar magnet

Strengths and weaknesses of NdFeB magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They retain magnetic properties for around 10 years – the drop is just ~1% (according to analyses),
• Neodymium magnets prove to be extremely resistant to magnetic field loss caused by external field sources,
• By applying a reflective layer of nickel, the element presents an aesthetic look,
• They feature high magnetic induction at the operating surface, making them more effective,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Thanks to freedom in shaping and the ability to modify to client solutions,
• Significant place in innovative solutions – they are used in HDD drives, electromotive mechanisms, advanced medical instruments, also multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which makes them useful in compact constructions

What to avoid - cons of neodymium magnets and ways of using them

• At very strong impacts they can break, therefore we advise placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as 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 advise using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Limited possibility of producing threads in the magnet and complicated shapes - preferred is a housing - mounting mechanism.
• Health risk resulting from small fragments of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child health protection. Furthermore, small components of these products are able to complicate diagnosis medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Detachment force of the magnet in optimal conditions – what it depends on?

The declared magnet strength refers to the limit force, recorded under optimal environment, namely:

• with the application of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• whose transverse dimension reaches at least 10 mm
• characterized by even structure
• under conditions of gap-free contact (metal-to-metal)
• for force acting at a right angle (in the magnet axis)
• at ambient temperature approx. 20 degrees Celsius

Key elements affecting lifting force

Bear in mind that the magnet holding will differ subject to the following factors, in order of importance:

• Clearance – the presence of foreign body (rust, tape, gap) acts as an insulator, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Force direction – note that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Base massiveness – insufficiently thick sheet does not accept the full field, causing part of the flux to be lost into the air.
• Metal type – different alloys attracts identically. Alloy additives weaken the interaction with the magnet.
• Surface structure – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
• Thermal factor – high temperature weakens magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was assessed with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, however under parallel forces the load capacity is reduced by as much as fivefold. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the holding force.