SM 25x250 [2xM8] / N42 - magnetic separator

Advantages and disadvantages of rare earth magnets.

Besides their immense field intensity, neodymium magnets offer the following advantages:

• Their magnetic field is maintained, and after approximately 10 years it decreases only by ~1% (according to research),
• Neodymium magnets are remarkably resistant to magnetic field loss caused by external field sources,
• A magnet with a metallic silver surface has an effective appearance,
• The surface of neodymium magnets generates a concentrated magnetic field – this is one of their assets,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Due to the possibility of accurate forming and customization to individualized solutions, magnetic components can be created in a broad palette of shapes and sizes, which increases their versatility,
• Universal use in future technologies – they are used in data components, electric motors, precision medical tools, also modern systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which makes them useful in compact constructions

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

• To avoid cracks under impact, we suggest using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets experience a drop in strength. 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 oxidize in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing nuts and complicated shapes in magnets, we recommend using cover - magnetic mount.
• Health risk resulting from small fragments of magnets pose a threat, if swallowed, which gains importance in the context of child health protection. Furthermore, small elements of these magnets can 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

Maximum lifting capacity of the magnet – what it depends on?

The lifting capacity listed is a result of laboratory testing executed under the following configuration:

• on a base made of mild steel, optimally conducting the magnetic flux
• possessing a massiveness of minimum 10 mm to avoid saturation
• with an ground touching surface
• with total lack of distance (without paint)
• for force applied at a right angle (in the magnet axis)
• at standard ambient temperature

Practical lifting capacity: influencing factors

Effective lifting capacity is influenced by specific conditions, including (from priority):

• Clearance – existence of foreign body (paint, tape, gap) acts as an insulator, which lowers power rapidly (even by 50% at 0.5 mm).
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Steel type – mild steel gives the best results. Alloy steels decrease magnetic properties and holding force.
• Plate texture – smooth surfaces ensure maximum contact, which increases field saturation. Uneven metal weaken the grip.
• Thermal environment – heating the magnet results in weakening of force. Check the thermal limit for a given model.

* Holding force was tested on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under parallel forces the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate decreases the load capacity.