MW 14x10 / N38 - cylindrical magnet

Strengths and weaknesses of NdFeB magnets.

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

• They retain magnetic properties for around 10 years – the drop is just ~1% (based on simulations),
• Magnets effectively resist against loss of magnetization caused by ambient magnetic noise,
• Thanks to the reflective finish, the layer of nickel, gold-plated, or silver gives an clean appearance,
• They show high magnetic induction at the operating surface, which affects their effectiveness,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures approaching 230°C and above...
• Possibility of accurate creating as well as optimizing to atypical conditions,
• Significant place in electronics industry – they are utilized in magnetic memories, motor assemblies, medical equipment, as well as industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which allows their use in small systems

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a strong case, which not only secures them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They oxidize in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing nuts and complicated forms in magnets, we recommend using cover - magnetic mechanism.
• Health risk related to microscopic parts of magnets can be dangerous, if swallowed, which is particularly important in the aspect of protecting the youngest. Additionally, small components of these devices are able to be problematic in diagnostics medical when they are in the body.
• With large orders the cost of neodymium magnets can be a barrier,

Detachment force of the magnet in optimal conditions – what it depends on?

Magnet power is the result of a measurement for optimal configuration, including:

• with the contact of a sheet made of low-carbon steel, guaranteeing maximum field concentration
• whose thickness equals approx. 10 mm
• characterized by even structure
• under conditions of gap-free contact (surface-to-surface)
• for force acting at a right angle (in the magnet axis)
• in temp. approx. 20°C

Lifting capacity in real conditions – factors

During everyday use, the actual holding force is determined by many variables, listed from most significant:

• Space between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – maximum parameter is available only during pulling at a 90° angle. The force required to slide of the magnet along the plate is usually several times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of generating force.
• Metal type – not every steel attracts identically. High carbon content weaken the attraction effect.
• Surface finish – ideal contact is possible only on smooth steel. Rough texture create air cushions, weakening the magnet.
• Thermal factor – high temperature weakens pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity was determined using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular pulling force, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the holding force.