SM 32x275 [2xM8] / N52 - magnetic separator

Advantages and disadvantages of neodymium magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They do not lose power, even over around 10 years – the drop in strength is only ~1% (according to tests),
• They retain their magnetic properties even under external field action,
• The use of an shiny coating of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• They feature high magnetic induction at the operating surface, making them more effective,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Possibility of individual creating as well as modifying to defined applications,
• Versatile presence in advanced technology sectors – they find application in hard drives, electric drive systems, advanced medical instruments, also modern systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution secures the magnet and simultaneously improves its durability.
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing threads and complicated forms in magnets, we recommend using casing - magnetic mechanism.
• Possible danger related to microscopic parts of magnets are risky, if swallowed, which becomes key in the context of child safety. It is also worth noting that small elements of these devices can disrupt the diagnostic process medical when they are in 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 it depends on?

The declared magnet strength concerns the peak performance, recorded under optimal environment, specifically:

• with the application of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• whose transverse dimension reaches at least 10 mm
• characterized by even structure
• with total lack of distance (without impurities)
• for force acting at a right angle (in the magnet axis)
• at temperature approx. 20 degrees Celsius

Determinants of lifting force in real conditions

Please note that the working load may be lower influenced by the following factors, in order of importance:

• Distance – existence of any layer (paint, dirt, gap) interrupts the magnetic circuit, which reduces capacity steeply (even by 50% at 0.5 mm).
• Direction of force – highest force is available only during perpendicular pulling. The shear force of the magnet along the surface is typically several times smaller (approx. 1/5 of the lifting capacity).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Plate material – mild steel attracts best. Higher carbon content decrease magnetic permeability and lifting capacity.
• Plate texture – smooth surfaces guarantee perfect abutment, which increases force. Uneven metal reduce efficiency.
• Thermal factor – high temperature weakens pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under perpendicular forces, whereas under parallel forces the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate reduces the lifting capacity.