SM 32x400 [2xM8] / N42 - magnetic separator

Pros as well as cons of NdFeB magnets.

Apart from their consistent holding force, neodymium magnets have these key benefits:

• They retain attractive force for nearly ten years – the drop is just ~1% (in theory),
• Neodymium magnets are extremely resistant to demagnetization caused by external interference,
• By applying a decorative coating of gold, the element acquires an professional look,
• Magnetic induction on the working layer of the magnet turns out to be impressive,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures reaching 230°C and above...
• Due to the ability of flexible molding and adaptation to specialized projects, NdFeB magnets can be manufactured in a wide range of shapes and sizes, which amplifies use scope,
• Fundamental importance in high-tech industry – they serve a role in hard drives, electric drive systems, precision medical tools, and other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which enables their usage in miniature devices

Disadvantages of NdFeB magnets:

• At strong impacts they can crack, therefore we recommend placing them in strong housings. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• NdFeB magnets lose power when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation as well as corrosion.
• Limited ability of creating threads in the magnet and complex shapes - preferred is casing - mounting mechanism.
• Possible danger related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the context of child health protection. Furthermore, small components of these products are able to be problematic in diagnostics medical after entering the body.
• With budget limitations the cost of neodymium magnets is economically unviable,

Breakaway strength of the magnet in ideal conditions – what contributes to it?

Magnet power is the result of a measurement for ideal contact conditions, taking into account:

• with the application of a yoke made of special test steel, guaranteeing maximum field concentration
• possessing a massiveness of at least 10 mm to ensure full flux closure
• characterized by even structure
• under conditions of no distance (metal-to-metal)
• for force applied at a right angle (pull-off, not shear)
• in neutral thermal conditions

Determinants of practical lifting force of a magnet

Effective lifting capacity is affected by working environment parameters, mainly (from most important):

• Distance – existence of foreign body (rust, tape, air) interrupts the magnetic circuit, which lowers capacity steeply (even by 50% at 0.5 mm).
• Angle of force application – maximum parameter is available only during perpendicular pulling. The shear force of the magnet along the plate is usually several times smaller (approx. 1/5 of the lifting capacity).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of generating force.
• Metal type – not every steel reacts the same. Alloy additives worsen the attraction effect.
• Surface condition – ground elements guarantee perfect abutment, which improves field saturation. Rough surfaces reduce efficiency.
• Heat – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity was assessed by applying a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate decreases the load capacity.