MW 12x1.5 / N38 - cylindrical magnet

Strengths and weaknesses of neodymium magnets.

Besides their exceptional strength, neodymium magnets offer the following advantages:

• They have unchanged lifting capacity, and over around 10 years their performance decreases symbolically – ~1% (according to theory),
• They are noted for resistance to demagnetization induced by presence of other magnetic fields,
• Thanks to the glossy finish, the plating of nickel, gold, or silver-plated gives an aesthetic appearance,
• Magnetic induction on the working layer of the magnet is strong,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• In view of the option of flexible forming and customization to individualized needs, NdFeB magnets can be manufactured in a wide range of forms and dimensions, which increases their versatility,
• Huge importance in future technologies – they are utilized in data components, electric motors, precision medical tools, as well as industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which enables their usage in compact constructions

Characteristics of disadvantages of neodymium magnets: application proposals

• At very strong impacts they can crack, therefore we advise placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• When exposed to high temperature, neodymium magnets suffer a drop in strength. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, in case of application outdoors
• Limited ability of producing threads in the magnet and complex forms - recommended is cover - magnetic holder.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which becomes key in the context of child health protection. It is also worth noting that small components of these devices are able to complicate diagnosis medical when they are in the body.
• Due to complex production process, their price is relatively high,

Best holding force of the magnet in ideal parameters – what it depends on?

Information about lifting capacity was determined for ideal contact conditions, taking into account:

• on a plate made of mild steel, perfectly concentrating the magnetic field
• with a cross-section minimum 10 mm
• with an polished contact surface
• with zero gap (no coatings)
• under axial application of breakaway force (90-degree angle)
• at standard ambient temperature

Lifting capacity in practice – influencing factors

Bear in mind that the application force may be lower subject to the following factors, starting with the most relevant:

• Gap between surfaces – every millimeter of distance (caused e.g. by varnish or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin plate does not close the flux, causing part of the flux to be lost to the other side.
• Material type – ideal substrate is high-permeability steel. Hardened steels may generate lower lifting capacity.
• Surface condition – ground elements ensure maximum contact, which improves force. Rough surfaces reduce efficiency.
• Temperature – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet and the plate lowers the holding force.