SM 25x175 [2xM8] / N52 - magnetic separator

Pros and cons of neodymium magnets.

Apart from their notable magnetism, neodymium magnets have these key benefits:

• They retain magnetic properties for nearly 10 years – the drop is just ~1% (in theory),
• Magnets perfectly protect themselves against demagnetization caused by external fields,
• By covering with a smooth coating of nickel, the element acquires an professional look,
• Neodymium magnets ensure maximum magnetic induction on a small area, which ensures high operational effectiveness,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and are able to act (depending on the shape) even at a temperature of 230°C or more...
• In view of the option of accurate forming and customization to unique solutions, magnetic components can be created in a wide range of forms and dimensions, which expands the range of possible applications,
• Significant place in advanced technology sectors – they find application in mass storage devices, drive modules, medical devices, as well as modern systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a special holder, which not only secures them against impacts but also raises their durability
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• We recommend cover - magnetic mount, due to difficulties in realizing threads inside the magnet and complex forms.
• Health risk related to microscopic parts of magnets pose a threat, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. Additionally, small components of these devices are able to disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Best holding force of the magnet in ideal parameters – what it depends on?

The declared magnet strength represents the peak performance, obtained under ideal test conditions, specifically:

• with the application of a yoke made of low-carbon steel, guaranteeing maximum field concentration
• with a cross-section of at least 10 mm
• with a plane cleaned and smooth
• with direct contact (no paint)
• for force acting at a right angle (in the magnet axis)
• at standard ambient temperature

Impact of factors on magnetic holding capacity in practice

Please note that the magnet holding may be lower influenced by the following factors, starting with the most relevant:

• Gap between magnet and steel – every millimeter of separation (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Plate thickness – insufficiently thick sheet causes magnetic saturation, causing part of the power to be wasted to the other side.
• Plate material – low-carbon steel attracts best. Alloy steels reduce magnetic properties and holding force.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Rough surfaces weaken the grip.
• Operating temperature – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was assessed using a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under parallel forces the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.