SM 32x375 [2xM8] / N42 - magnetic separator

Advantages and disadvantages of neodymium magnets.

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

• They have stable power, and over more than ten years their performance decreases symbolically – ~1% (according to theory),
• They maintain their magnetic properties even under strong external field,
• The use of an elegant finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Magnets are characterized by very high magnetic induction on the working surface,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• In view of the potential of free forming and adaptation to custom projects, magnetic components can be manufactured in a variety of forms and dimensions, which amplifies use scope,
• Key role in advanced technology sectors – they find application in hard drives, electric motors, medical equipment, also complex engineering applications.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Disadvantages of neodymium magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a special holder, which not only protects them against impacts but also raises their durability
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing nuts and complex forms in magnets, we recommend using a housing - magnetic holder.
• Possible danger related to microscopic parts of magnets can be dangerous, in case of ingestion, which is particularly important in the context of child health protection. Furthermore, tiny parts of these devices are able to complicate diagnosis medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which can limit application in large quantities

Optimal lifting capacity of a neodymium magnet – what affects it?

The declared magnet strength represents the maximum value, recorded under ideal test conditions, specifically:

• on a plate made of structural steel, perfectly concentrating the magnetic flux
• with a thickness no less than 10 mm
• characterized by lack of roughness
• with direct contact (without coatings)
• during detachment in a direction perpendicular to the plane
• at ambient temperature room level

Practical lifting capacity: influencing factors

Holding efficiency is affected by working environment parameters, including (from most important):

• Clearance – existence of foreign body (rust, tape, air) acts as an insulator, which lowers power rapidly (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is obtained only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Material composition – different alloys attracts identically. Alloy additives worsen the attraction effect.
• Surface finish – full contact is possible only on smooth steel. Any scratches and bumps create air cushions, weakening the magnet.
• Temperature – temperature increase causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under shearing force the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate decreases the lifting capacity.