SM 32x125 [2xM8] / N52 - magnetic separator

Advantages and disadvantages of rare earth magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They virtually do not lose power, because even after 10 years the performance loss is only ~1% (according to literature),
• Neodymium magnets remain highly resistant to loss of magnetic properties caused by external interference,
• In other words, due to the glossy surface of nickel, the element gains visual value,
• Magnetic induction on the surface of the magnet remains impressive,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of individual forming and adapting to complex needs,
• Huge importance in modern technologies – they are utilized in computer drives, electromotive mechanisms, medical equipment, and industrial machines.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• At very strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Limited ability of making nuts in the magnet and complicated forms - preferred is a housing - magnet mounting.
• Health risk related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products are able to complicate diagnosis medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Highest magnetic holding force – what it depends on?

The load parameter shown concerns the maximum value, obtained under optimal environment, specifically:

• with the contact of a sheet made of special test steel, ensuring full magnetic saturation
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with an ground contact surface
• with total lack of distance (no coatings)
• for force applied at a right angle (in the magnet axis)
• in stable room temperature

Impact of factors on magnetic holding capacity in practice

Real force is influenced by working environment parameters, such as (from priority):

• Clearance – the presence of foreign body (paint, dirt, air) interrupts the magnetic circuit, which lowers capacity steeply (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet exhibits significantly lower power (often approx. 20-30% of maximum force).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Metal type – different alloys reacts the same. High carbon content worsen the interaction with the magnet.
• Surface quality – the more even the plate, the better the adhesion and stronger the hold. Roughness acts like micro-gaps.
• Temperature influence – high temperature weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity was measured with the use of a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, in contrast under shearing force the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate decreases the load capacity.