AM Haczyk M4 - magnetic accessories

Strengths and weaknesses of neodymium magnets.

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

• They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (in laboratory conditions),
• They are noted for resistance to demagnetization induced by external disturbances,
• The use of an metallic layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• The surface of neodymium magnets generates a maximum magnetic field – this is a distinguishing feature,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for functioning at temperatures reaching 230°C and above...
• Possibility of precise shaping as well as optimizing to individual requirements,
• Versatile presence in innovative solutions – they are commonly used in magnetic memories, electric drive systems, medical equipment, as well as modern systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also improves its resistance to damage
• Neodymium magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (a factor is the shape as well as 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 during using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in realizing nuts and complicated forms in magnets, we propose using casing - magnetic mount.
• Potential hazard to health – tiny shards of magnets can be dangerous, if swallowed, which is particularly important in the context of child safety. Furthermore, small elements of these products are able to disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Detachment force of the magnet in optimal conditions – what contributes to it?

Magnet power was defined for optimal configuration, including:

• with the contact of a sheet made of special test steel, guaranteeing maximum field concentration
• possessing a thickness of minimum 10 mm to ensure full flux closure
• characterized by lack of roughness
• without any insulating layer between the magnet and steel
• for force acting at a right angle (in the magnet axis)
• at ambient temperature room level

Lifting capacity in real conditions – factors

In real-world applications, the actual holding force is determined by a number of factors, ranked from most significant:

• Distance (betwixt the magnet and the plate), since even a tiny distance (e.g. 0.5 mm) leads to a reduction in force by up to 50% (this also applies to paint, corrosion or dirt).
• Angle of force application – highest force is obtained only during pulling at a 90° angle. The shear force of the magnet along the plate is standardly many times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Material composition – not every steel attracts identically. High carbon content weaken the attraction effect.
• Smoothness – full contact is possible only on polished steel. Rough texture reduce the real contact area, weakening the magnet.
• Temperature influence – hot environment reduces magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, in contrast under parallel forces the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate reduces the holding force.