UMP 75x24 [M8+M10] GW F 200 kg - search holder

Strengths and weaknesses of neodymium magnets.

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

• They do not lose power, even over around 10 years – the decrease in lifting capacity is only ~1% (based on measurements),
• They are resistant to demagnetization induced by external disturbances,
• In other words, due to the smooth surface of gold, the element gains visual value,
• Magnets are distinguished by impressive magnetic induction on the active area,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to versatility in forming and the ability to customize to client solutions,
• Universal use in innovative solutions – they are utilized in mass storage devices, brushless drives, medical equipment, also complex engineering applications.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

What to avoid - cons of neodymium magnets and proposals for their use:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also increases its resistance to damage
• NdFeB magnets lose power when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation as well as corrosion.
• We recommend a housing - magnetic holder, due to difficulties in realizing nuts inside the magnet and complex shapes.
• Health risk resulting from small fragments of magnets pose a threat, in case of ingestion, which becomes key in the context of child health protection. It is also worth noting that tiny parts of these products are able to complicate diagnosis medical after entering the body.
• Due to neodymium price, their price exceeds standard values,

Maximum magnetic pulling force – what it depends on?

Breakaway force was determined for the most favorable conditions, assuming:

• on a plate made of mild steel, effectively closing the magnetic flux
• possessing a thickness of min. 10 mm to avoid saturation
• with an ideally smooth touching surface
• with total lack of distance (no impurities)
• under vertical force direction (90-degree angle)
• at conditions approx. 20°C

Determinants of practical lifting force of a magnet

Effective lifting capacity is affected by specific conditions, mainly (from most important):

• Space between surfaces – every millimeter of distance (caused e.g. by varnish or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of converting into lifting capacity.
• Chemical composition of the base – mild steel gives the best results. Higher carbon content decrease magnetic properties and lifting capacity.
• Surface structure – the smoother and more polished the plate, the better the adhesion and stronger the hold. Unevenness creates an air distance.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity was determined by applying a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, however under shearing force the holding force is lower. Additionally, even a small distance {between} the magnet and the plate reduces the load capacity.