SM 32x275 [2xM8] / N42 - magnetic separator

Pros and cons of rare earth magnets.

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

• They retain full power for around 10 years – the loss is just ~1% (based on simulations),
• They feature excellent resistance to magnetism drop when exposed to opposing magnetic fields,
• Thanks to the glossy finish, the coating of nickel, gold, or silver gives an professional appearance,
• Magnetic induction on the working part of the magnet remains extremely intense,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures reaching 230°C and above...
• Possibility of custom modeling and adapting to defined conditions,
• Universal use in modern industrial fields – they are commonly used in hard drives, electric motors, advanced medical instruments, also complex engineering applications.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Disadvantages of neodymium magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only shields the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their strength 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 during using outdoors, we recommend using waterproof magnets made of rubber, plastic or other material protecting against moisture
• We suggest cover - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complex forms.
• Potential hazard to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Furthermore, small components of these products are able to disrupt the diagnostic process medical in case of swallowing.
• Due to expensive raw materials, their price is higher than average,

Maximum lifting capacity of the magnet – what contributes to it?

Information about lifting capacity is the result of a measurement for the most favorable conditions, taking into account:

• using a base made of mild steel, serving as a circuit closing element
• whose thickness equals approx. 10 mm
• characterized by smoothness
• with zero gap (without paint)
• under axial force direction (90-degree angle)
• at conditions approx. 20°C

Key elements affecting lifting force

Bear in mind that the magnet holding will differ influenced by elements below, starting with the most relevant:

• Gap (between the magnet and the metal), because even a microscopic distance (e.g. 0.5 mm) can cause a reduction in force by up to 50% (this also applies to paint, corrosion or dirt).
• Force direction – declared lifting capacity refers to pulling vertically. When slipping, the magnet holds much less (often approx. 20-30% of maximum force).
• Plate thickness – insufficiently thick steel causes magnetic saturation, causing part of the flux to be lost into the air.
• Steel grade – the best choice is high-permeability steel. Cast iron may generate lower lifting capacity.
• Surface quality – the more even the plate, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Temperature influence – high temperature reduces magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity was assessed by applying a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under shearing force the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet’s surface and the plate decreases the load capacity.