MP 12x8/4x3 / N38 - ring magnet

Pros as well as cons of rare earth magnets.

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

• Their magnetic field is durable, and after approximately ten years it drops only by ~1% (according to research),
• They do not lose their magnetic properties even under close interference source,
• In other words, due to the shiny finish of silver, the element gains visual value,
• 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, enabling action at temperatures approaching 230°C and above...
• Thanks to flexibility in forming and the ability to modify to complex applications,
• Huge importance in modern technologies – they are used in computer drives, drive modules, medical devices, as well as other advanced devices.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Cons of neodymium magnets and proposals for their use:

• To avoid cracks under impact, we recommend using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing threads and complex shapes in magnets, we propose using casing - magnetic holder.
• Health risk resulting from small fragments of magnets pose a threat, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products are able to be problematic in diagnostics medical in case of swallowing.
• Due to neodymium price, their price is relatively high,

Magnetic strength at its maximum – what affects it?

The force parameter is a theoretical maximum value conducted under standard conditions:

• using a sheet made of low-carbon steel, functioning as a magnetic yoke
• with a cross-section of at least 10 mm
• with a plane perfectly flat
• without the slightest insulating layer between the magnet and steel
• under axial application of breakaway force (90-degree angle)
• at temperature room level

Key elements affecting lifting force

It is worth knowing that the working load may be lower subject to elements below, in order of importance:

• Distance (between the magnet and the metal), because even a microscopic distance (e.g. 0.5 mm) leads to a reduction in force by up to 50% (this also applies to paint, rust or dirt).
• Force direction – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Chemical composition of the base – low-carbon steel attracts best. Alloy steels reduce magnetic properties and holding force.
• Smoothness – full contact is obtained only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal factor – high temperature weakens pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was assessed using a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. In addition, even a minimal clearance {between} the magnet and the plate lowers the load capacity.