HH 16x5.3 [M3] / N38 - through hole magnetic holder

Advantages as well as disadvantages of NdFeB magnets.

Apart from their strong power, neodymium magnets have these key benefits:

• Their strength remains stable, and after approximately ten years it drops only by ~1% (theoretically),
• Magnets very well defend themselves against demagnetization caused by ambient magnetic noise,
• The use of an metallic layer of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Magnets possess extremely high magnetic induction on the outer side,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Due to the option of precise molding and customization to custom needs, magnetic components can be manufactured in a broad palette of forms and dimensions, which increases their versatility,
• Universal use in electronics industry – they are utilized in HDD drives, brushless drives, medical equipment, and industrial machines.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets and ways of using them

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
• Neodymium magnets lose power when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• We recommend cover - magnetic mechanism, due to difficulties in producing threads inside the magnet and complicated forms.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that tiny parts of these magnets are able to 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

Optimal lifting capacity of a neodymium magnet – what contributes to it?

Breakaway force was defined for ideal contact conditions, taking into account:

• on a plate made of mild steel, perfectly concentrating the magnetic field
• with a thickness of at least 10 mm
• characterized by smoothness
• under conditions of no distance (metal-to-metal)
• for force acting at a right angle (pull-off, not shear)
• in neutral thermal conditions

Lifting capacity in practice – influencing factors

Bear in mind that the working load will differ depending on the following factors, starting with the most relevant:

• Space between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is available only during perpendicular pulling. The shear force of the magnet along the plate is standardly several times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of converting into lifting capacity.
• Material type – the best choice is pure iron steel. Stainless steels may have worse magnetic properties.
• Surface finish – full contact is possible only on polished steel. Any scratches and bumps reduce the real contact area, reducing force.
• Temperature influence – hot environment weakens magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was performed on a smooth plate of suitable thickness, under perpendicular forces, whereas under attempts to slide the magnet the holding force is lower. In addition, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.