NCM 10x13.5x5 / N38 - channel magnetic holder

Strengths as well as weaknesses of rare earth magnets.

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

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (in laboratory conditions),
• Neodymium magnets are characterized by remarkably resistant to loss of magnetic properties caused by external magnetic fields,
• Thanks to the smooth finish, the plating of Ni-Cu-Ni, gold-plated, or silver gives an clean appearance,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Thanks to resistance to high temperature, they are capable of working (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of detailed shaping and adapting to specific conditions,
• Universal use in modern industrial fields – they are utilized in computer drives, brushless drives, advanced medical instruments, as well as other advanced devices.
• 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 heavy impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets decrease 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 stability even at temperatures up to 230°C
• They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in creating nuts and complex forms in magnets, we recommend using casing - magnetic mount.
• Possible danger resulting from small fragments of magnets can be dangerous, in case of ingestion, which gains importance in the aspect of protecting the youngest. It is also worth noting that tiny parts of these devices can disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Breakaway strength of the magnet in ideal conditions – what contributes to it?

Information about lifting capacity was defined for optimal configuration, including:

• with the use of a sheet made of low-carbon steel, ensuring maximum field concentration
• with a thickness minimum 10 mm
• with an polished contact surface
• without any air gap between the magnet and steel
• for force applied at a right angle (in the magnet axis)
• at standard ambient temperature

Lifting capacity in practice – influencing factors

During everyday use, the real power is determined by a number of factors, presented from crucial:

• Gap between surfaces – every millimeter of distance (caused e.g. by veneer or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Force direction – remember that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Steel grade – the best choice is high-permeability steel. Stainless steels may generate lower lifting capacity.
• Plate texture – smooth surfaces ensure maximum contact, which improves field saturation. Uneven metal weaken the grip.
• Thermal environment – heating the magnet results in weakening of force. Check the maximum operating temperature for a given model.

* Lifting capacity was determined by applying a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, in contrast under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet and the plate lowers the load capacity.