AM szekla [M10] - magnetic accessories

Strengths and weaknesses of neodymium magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They do not lose power, even after approximately 10 years – the drop in power is only ~1% (according to tests),
• They maintain their magnetic properties even under strong external field,
• A magnet with a metallic silver surface has an effective appearance,
• The surface of neodymium magnets generates a concentrated magnetic field – this is a distinguishing feature,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, allowing for operation at temperatures reaching 230°C and above...
• Thanks to freedom in designing and the ability to adapt to client solutions,
• Significant place in innovative solutions – they find application in mass storage devices, brushless drives, medical equipment, also technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which makes them useful in compact constructions

Problematic aspects of neodymium magnets: tips and applications.

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore during using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• We recommend casing - magnetic mount, due to difficulties in creating threads inside the magnet and complex shapes.
• Potential hazard related to microscopic parts 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 magnets are able to disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which hinders application in large quantities

Breakaway strength of the magnet in ideal conditions – what it depends on?

Holding force of 320 kg is a result of laboratory testing conducted under specific, ideal conditions:

• with the use of a sheet made of low-carbon steel, ensuring full magnetic saturation
• whose transverse dimension is min. 10 mm
• with an polished touching surface
• without the slightest air gap between the magnet and steel
• for force applied at a right angle (in the magnet axis)
• at ambient temperature approx. 20 degrees Celsius

Impact of factors on magnetic holding capacity in practice

During everyday use, the actual holding force is determined by several key aspects, ranked from the most important:

• Air gap (betwixt the magnet and the plate), as even a microscopic distance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
• Force direction – declared lifting capacity refers to detachment vertically. When slipping, the magnet holds significantly lower power (typically approx. 20-30% of nominal force).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of generating force.
• Chemical composition of the base – low-carbon steel gives the best results. Alloy admixtures lower magnetic properties and holding force.
• Surface quality – the more even the plate, the larger the contact zone and stronger the hold. Roughness creates an air distance.
• Temperature – heating the magnet results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, however under parallel forces the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet and the plate decreases the load capacity.