CM PML-3 / N45 - magnetic gripper

Advantages as well as disadvantages of NdFeB magnets.

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

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (in laboratory conditions),
• Neodymium magnets remain remarkably resistant to magnetic field loss caused by external magnetic fields,
• Thanks to the shimmering finish, the layer of Ni-Cu-Ni, gold, or silver-plated gives an modern appearance,
• Magnetic induction on the top side of the magnet remains maximum,
• Neodymium magnets are known for strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the magnetic form),
• Due to the option of free forming and adaptation to specialized requirements, NdFeB magnets can be modeled in a variety of forms and dimensions, which expands the range of possible applications,
• Versatile presence in high-tech industry – they find application in computer drives, electric drive systems, medical devices, and technologically advanced constructions.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets and proposals for their use:

• They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets suffer a drop in force. 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
• 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, in case of application outdoors
• Limited ability of producing threads in the magnet and complex forms - preferred is a housing - mounting mechanism.
• Possible danger resulting from small fragments of magnets are risky, in case of ingestion, which becomes key in the aspect of protecting the youngest. It is also worth noting that small components of these devices are able to complicate diagnosis medical after entering the body.
• With budget limitations the cost of neodymium magnets can be a barrier,

Maximum magnetic pulling force – what affects it?

Breakaway force is the result of a measurement for optimal configuration, assuming:

• using a base made of mild steel, serving as a circuit closing element
• whose thickness is min. 10 mm
• characterized by lack of roughness
• without the slightest clearance between the magnet and steel
• during detachment in a direction perpendicular to the plane
• at room temperature

Impact of factors on magnetic holding capacity in practice

In real-world applications, the actual lifting capacity depends on many variables, ranked from most significant:

• Distance (betwixt the magnet and the metal), as even a tiny distance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
• Load vector – maximum parameter is reached only during perpendicular pulling. The force required to slide of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Base massiveness – insufficiently thick sheet does not close the flux, causing part of the flux to be wasted to the other side.
• Metal type – different alloys attracts identically. Alloy additives weaken the attraction effect.
• Surface condition – ground elements guarantee perfect abutment, which improves field saturation. Uneven metal weaken the grip.
• Thermal environment – temperature increase results in weakening of induction. Check the thermal limit for a given model.

* Lifting capacity testing was conducted on plates with a smooth surface of suitable thickness, under perpendicular forces, whereas under shearing force the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet and the plate reduces the load capacity.