SM 25x150 [2xM8] / N42 - magnetic separator

Pros as well as cons of rare earth magnets.

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

• They do not lose strength, even during around 10 years – the drop in lifting capacity is only ~1% (according to tests),
• They do not lose their magnetic properties even under strong external field,
• In other words, due to the reflective finish of silver, the element gains visual value,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling functioning at temperatures reaching 230°C and above...
• Thanks to the potential of precise forming and customization to unique projects, NdFeB magnets can be produced in a wide range of shapes and sizes, which amplifies use scope,
• Versatile presence in future technologies – they find application in mass storage devices, brushless drives, diagnostic systems, and complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which makes them useful in small systems

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as 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 while using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited possibility of producing nuts in the magnet and complicated forms - recommended is a housing - mounting mechanism.
• Potential hazard resulting from small fragments of magnets pose a threat, if swallowed, which gains importance in the context of child safety. Furthermore, small elements of these magnets can disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which hinders application in large quantities

Highest magnetic holding force – what it depends on?

Breakaway force was defined for the most favorable conditions, including:

• using a base made of low-carbon steel, acting as a magnetic yoke
• with a thickness minimum 10 mm
• with a plane cleaned and smooth
• under conditions of no distance (metal-to-metal)
• under perpendicular force direction (90-degree angle)
• in neutral thermal conditions

Magnet lifting force in use – key factors

During everyday use, the actual lifting capacity is determined by a number of factors, ranked from most significant:

• Distance – existence of foreign body (rust, tape, gap) interrupts the magnetic circuit, which lowers power rapidly (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to detachment vertically. When applying parallel force, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of generating force.
• Steel grade – the best choice is high-permeability steel. Cast iron may generate lower lifting capacity.
• Surface condition – ground elements ensure maximum contact, which increases field saturation. Uneven metal weaken the grip.
• Temperature influence – high temperature reduces pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under a perpendicular pulling force, in contrast under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.