CM PML-10 / N45 - magnetic gripper

Strengths and weaknesses of rare earth magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• Their magnetic field remains stable, and after approximately ten years it decreases only by ~1% (according to research),
• Magnets very well resist against loss of magnetization caused by foreign field sources,
• The use of an refined coating of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to modularity in constructing and the ability to adapt to complex applications,
• Universal use in electronics industry – they serve a role in data components, electric motors, medical devices, also industrial machines.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 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
• Due to limitations in realizing nuts and complicated shapes in magnets, we recommend using casing - magnetic mount.
• Potential hazard related to microscopic parts of magnets are risky, in case of ingestion, which becomes key in the context of child health protection. Additionally, tiny parts of these products can disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Magnetic strength at its maximum – what affects it?

Breakaway force was determined for ideal contact conditions, including:

• on a plate made of mild steel, perfectly concentrating the magnetic flux
• possessing a massiveness of min. 10 mm to ensure full flux closure
• characterized by smoothness
• under conditions of gap-free contact (metal-to-metal)
• under vertical force direction (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

Key elements affecting lifting force

Real force impacted by working environment parameters, mainly (from most important):

• Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Chemical composition of the base – mild steel attracts best. Alloy steels decrease magnetic properties and lifting capacity.
• Base smoothness – the smoother and more polished the plate, the larger the contact zone and stronger the hold. Roughness creates an air distance.
• Heat – NdFeB sinters have a negative temperature coefficient. When it is hot they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was conducted on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet’s surface and the plate reduces the load capacity.