MW 9x3 / N38 - cylindrical magnet

Pros as well as cons of neodymium magnets.

Besides their remarkable pulling force, neodymium magnets offer the following advantages:

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (in laboratory conditions),
• They have excellent resistance to magnetic field loss as a result of external magnetic sources,
• Thanks to the reflective finish, the coating of Ni-Cu-Ni, gold-plated, or silver gives an elegant appearance,
• Magnetic induction on the surface of the magnet turns out to be extremely intense,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• In view of the possibility of accurate molding and customization to specialized needs, magnetic components can be created in a broad palette of geometric configurations, which makes them more universal,
• Versatile presence in electronics industry – they are commonly used in mass storage devices, electric drive systems, medical devices, and complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which enables their usage in compact constructions

Disadvantages of NdFeB magnets:

• At strong impacts they can crack, therefore we advise placing them in special holders. A metal housing provides additional protection against damage and increases the magnet's durability.
• When exposed to high temperature, neodymium magnets experience a drop in force. 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 suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Limited ability of making threads in the magnet and complex forms - preferred is cover - magnetic holder.
• Potential hazard related to microscopic parts of magnets are risky, when accidentally swallowed, which is particularly important in the context of child safety. It is also worth noting that small components of these products can be problematic in diagnostics medical after entering the body.
• With mass production the cost of neodymium magnets is a challenge,

Maximum lifting capacity of the magnet – what affects it?

Holding force of 1.49 kg is a theoretical maximum value executed under the following configuration:

• with the application of a sheet made of low-carbon steel, guaranteeing maximum field concentration
• possessing a thickness of at least 10 mm to avoid saturation
• characterized by smoothness
• under conditions of ideal adhesion (surface-to-surface)
• for force applied at a right angle (pull-off, not shear)
• in stable room temperature

Lifting capacity in practice – influencing factors

Effective lifting capacity is affected by working environment parameters, including (from priority):

• Gap (betwixt the magnet and the metal), as even a microscopic distance (e.g. 0.5 mm) results in a decrease in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
• Angle of force application – maximum parameter is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the plate is typically many times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – for full efficiency, the steel must be adequately massive. Thin sheet limits the attraction force (the magnet "punches through" it).
• Material type – ideal substrate is pure iron steel. Hardened steels may attract less.
• Surface structure – the more even the surface, the larger the contact zone and stronger the hold. Roughness acts like micro-gaps.
• Thermal environment – heating the magnet results in weakening of induction. Check the thermal limit for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.