FM Ruszt magnetyczny do leja fi 200 dwupoziomowy / N52 - magnetic filter

Advantages as well as disadvantages of NdFeB magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They retain attractive force for nearly 10 years – the drop is just ~1% (according to analyses),
• They possess excellent resistance to weakening of magnetic properties when exposed to external magnetic sources,
• A magnet with a smooth gold surface has better aesthetics,
• Magnetic induction on the working part of the magnet is strong,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Possibility of exact modeling as well as adjusting to atypical applications,
• Huge importance in future technologies – they are used in mass storage devices, brushless drives, precision medical tools, also modern systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets: application proposals

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only protects the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in force. 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
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Limited ability of producing nuts in the magnet and complicated forms - preferred is casing - magnetic holder.
• Health risk resulting from small fragments of magnets can be dangerous, if swallowed, which gains importance in the aspect of protecting the youngest. Furthermore, tiny parts of these magnets can complicate diagnosis medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which can limit application in large quantities

Optimal lifting capacity of a neodymium magnet – what affects it?

The load parameter shown represents the limit force, obtained under ideal test conditions, namely:

• on a base made of structural steel, optimally conducting the magnetic field
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by even structure
• under conditions of ideal adhesion (metal-to-metal)
• for force acting at a right angle (in the magnet axis)
• in temp. approx. 20°C

Lifting capacity in real conditions – factors

In practice, the real power results from many variables, ranked from crucial:

• Space between surfaces – every millimeter of separation (caused e.g. by varnish or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Load vector – highest force is obtained only during pulling at a 90° angle. The shear force of the magnet along the surface is standardly several times smaller (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin steel does not accept the full field, causing part of the flux to be escaped to the other side.
• Material type – the best choice is high-permeability steel. Hardened steels may attract less.
• Surface quality – the more even the surface, the better the adhesion and higher the lifting capacity. Unevenness acts like micro-gaps.
• Thermal factor – hot environment reduces pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a slight gap {between} the magnet’s surface and the plate reduces the load capacity.