SM 32x225 [2xM8] / N52 - magnetic separator

Pros and cons of rare earth magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• Their strength is durable, and after approximately ten years it decreases only by ~1% (according to research),
• They maintain their magnetic properties even under strong external field,
• Thanks to the metallic finish, the plating of Ni-Cu-Ni, gold-plated, or silver-plated gives an clean appearance,
• They feature high magnetic induction at the operating surface, which increases their power,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Possibility of custom shaping as well as adjusting to complex needs,
• Versatile presence in modern technologies – they are utilized in computer drives, brushless drives, precision medical tools, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which makes them useful in compact constructions

Disadvantages of neodymium magnets:

• Brittleness is one of their disadvantages. Upon intense impact they can break. We recommend keeping them in a steel housing, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• We recommend casing - magnetic holder, due to difficulties in producing nuts inside the magnet and complex shapes.
• Potential hazard related to microscopic parts of magnets are risky, if swallowed, which is particularly important in the context of child health protection. It is also worth noting that small components of these devices can 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?

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

• with the use of a sheet made of special test steel, guaranteeing full magnetic saturation
• with a cross-section minimum 10 mm
• characterized by even structure
• under conditions of ideal adhesion (metal-to-metal)
• under perpendicular application of breakaway force (90-degree angle)
• at conditions approx. 20°C

Key elements affecting lifting force

Holding efficiency is influenced by specific conditions, mainly (from priority):

• Distance – the presence of foreign body (paint, dirt, gap) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is obtained only during perpendicular pulling. The force required to slide of the magnet along the surface is typically several times smaller (approx. 1/5 of the lifting capacity).
• Wall thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Steel type – mild steel attracts best. Alloy steels lower magnetic properties and holding force.
• Surface condition – ground elements ensure maximum contact, which increases force. Rough surfaces weaken the grip.
• Operating temperature – NdFeB sinters have a sensitivity to temperature. When it is hot they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Additionally, even a slight gap {between} the magnet and the plate decreases the lifting capacity.