SM 18x100 [2xM5] / N42 - magnetic separator

Strengths and weaknesses of NdFeB magnets.

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

• They do not lose magnetism, even during around 10 years – the reduction in lifting capacity is only ~1% (theoretically),
• They maintain their magnetic properties even under strong external field,
• By covering with a smooth coating of silver, the element presents an elegant look,
• They show high magnetic induction at the operating surface, which increases their power,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to the potential of precise forming and adaptation to unique projects, magnetic components can be produced in a variety of forms and dimensions, which amplifies use scope,
• Universal use in modern technologies – they are used in magnetic memories, drive modules, diagnostic systems, and industrial machines.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Characteristics of disadvantages of neodymium magnets and ways of using them

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets using a steel holder. 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 strength. Often, when the temperature exceeds 80°C, their strength 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
• Due to limitations in realizing nuts and complex forms in magnets, we recommend using casing - magnetic holder.
• Possible danger to health – tiny shards of magnets are risky, when accidentally swallowed, which is particularly important in the context of child safety. Additionally, small elements of these magnets are able to complicate diagnosis medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

Breakaway strength of the magnet in ideal conditions – what contributes to it?

The force parameter is a result of laboratory testing performed under specific, ideal conditions:

• using a plate made of low-carbon steel, functioning as a ideal flux conductor
• with a cross-section minimum 10 mm
• with an ground contact surface
• with zero gap (without impurities)
• for force applied at a right angle (pull-off, not shear)
• at temperature room level

Impact of factors on magnetic holding capacity in practice

During everyday use, the actual lifting capacity is determined by several key aspects, ranked from most significant:

• Clearance – existence of any layer (rust, dirt, gap) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Load vector – highest force is reached only during perpendicular pulling. The force required to slide of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Steel grade – ideal substrate is pure iron steel. Cast iron may generate lower lifting capacity.
• Surface structure – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Unevenness creates an air distance.
• Temperature influence – high temperature reduces magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a minimal clearance {between} the magnet’s surface and the plate decreases the load capacity.