MW 10x10 / N38 - cylindrical magnet

Pros as well as cons of rare earth magnets.

Besides their remarkable field intensity, neodymium magnets offer the following advantages:

• They retain magnetic properties for nearly ten years – the loss is just ~1% (according to analyses),
• Neodymium magnets are characterized by exceptionally resistant to demagnetization caused by magnetic disturbances,
• A magnet with a metallic gold surface is more attractive,
• Magnets are distinguished by very high magnetic induction on the surface,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling functioning at temperatures approaching 230°C and above...
• Possibility of precise shaping as well as modifying to concrete conditions,
• Versatile presence in future technologies – they are utilized in HDD drives, drive modules, advanced medical instruments, and complex engineering applications.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of neodymium magnets:

• Brittleness is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a steel housing, which not only secures them against impacts but also raises their durability
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Due to limitations in producing nuts and complex shapes in magnets, we propose using a housing - magnetic mechanism.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which is particularly important in the context of child safety. Additionally, tiny parts of these devices are able to be problematic in diagnostics medical after entering the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which can limit application in large quantities

Detachment force of the magnet in optimal conditions – what contributes to it?

Breakaway force is the result of a measurement for ideal contact conditions, assuming:

• with the application of a sheet made of special test steel, ensuring full magnetic saturation
• possessing a massiveness of min. 10 mm to avoid saturation
• with an ideally smooth contact surface
• without any clearance between the magnet and steel
• for force applied at a right angle (in the magnet axis)
• at conditions approx. 20°C

Impact of factors on magnetic holding capacity in practice

Effective lifting capacity impacted by specific conditions, including (from priority):

• Space between surfaces – every millimeter of separation (caused e.g. by varnish or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Element thickness – for full efficiency, the steel must be adequately massive. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Material composition – not every steel reacts the same. Alloy additives worsen the attraction effect.
• Surface finish – full contact is possible only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and in frost they can be stronger (up to a certain limit).

* Holding force was measured on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.