SM 32x200 [2xM8] / N52 - magnetic separator

Advantages and disadvantages of rare earth magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They have unchanged lifting capacity, and over more than 10 years their performance decreases symbolically – ~1% (according to theory),
• They are resistant to demagnetization induced by external field influence,
• By applying a decorative coating of silver, the element has an modern look,
• Magnetic induction on the working part of the magnet turns out to be very high,
• Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
• Considering the possibility of accurate molding and customization to custom projects, neodymium magnets can be manufactured in a broad palette of forms and dimensions, which makes them more universal,
• Key role in electronics industry – they find application in computer drives, electric drive systems, precision medical tools, as well as modern systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which makes them useful in small systems

Disadvantages of NdFeB magnets:

• At very strong impacts they can crack, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• When exposed to high temperature, neodymium magnets experience a drop in power. 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
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• We recommend cover - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complex forms.
• Health risk related to microscopic parts of magnets pose a threat, when accidentally swallowed, which gains importance in the aspect of protecting the youngest. Additionally, small elements of these magnets are able to be problematic in diagnostics medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Magnetic strength at its maximum – what affects it?

Information about lifting capacity is the result of a measurement for optimal configuration, including:

• with the use of a sheet made of low-carbon steel, ensuring maximum field concentration
• with a cross-section of at least 10 mm
• with an ground touching surface
• without any clearance between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• at conditions approx. 20°C

Key elements affecting lifting force

It is worth knowing that the magnet holding will differ depending on elements below, in order of importance:

• Clearance – existence of foreign body (rust, dirt, gap) acts as an insulator, which lowers power steeply (even by 50% at 0.5 mm).
• Angle of force application – maximum parameter is available only during pulling at a 90° angle. The shear force of the magnet along the surface is usually several times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Material composition – different alloys attracts identically. Alloy additives weaken the attraction effect.
• Surface condition – ground elements guarantee perfect abutment, which improves force. Uneven metal weaken the grip.
• Temperature influence – hot environment weakens pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was conducted on plates with a smooth surface of suitable thickness, under perpendicular forces, in contrast under attempts to slide the magnet the holding force is lower. Additionally, even a slight gap {between} the magnet’s surface and the plate decreases the lifting capacity.