MW 5x15 / N38 - cylindrical magnet

Advantages and disadvantages of NdFeB magnets.

Besides their remarkable strength, neodymium magnets offer the following advantages:

• They have unchanged lifting capacity, and over nearly 10 years their attraction force decreases symbolically – ~1% (according to theory),
• They possess excellent resistance to magnetism drop when exposed to opposing magnetic fields,
• In other words, due to the smooth surface of nickel, the element is aesthetically pleasing,
• Magnets have exceptionally strong magnetic induction on the surface,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Considering the possibility of accurate molding and adaptation to individualized solutions, NdFeB magnets can be created in a variety of forms and dimensions, which expands the range of possible applications,
• Universal use in modern industrial fields – they are used in computer drives, brushless drives, medical equipment, as well as technologically advanced constructions.
• Thanks to efficiency per cm³, small magnets offer high operating force, in miniature format,

Characteristics of disadvantages of neodymium magnets and ways of using them

• They are fragile upon too strong 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
• Neodymium magnets lose strength 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Due to limitations in producing nuts and complex forms in magnets, we recommend using a housing - magnetic holder.
• Possible danger resulting from small fragments 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 be problematic in diagnostics medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which can limit application in large quantities

Breakaway strength of the magnet in ideal conditions – what it depends on?

The specified lifting capacity refers to the maximum value, recorded under laboratory conditions, meaning:

• with the contact of a sheet made of low-carbon steel, guaranteeing maximum field concentration
• whose transverse dimension equals approx. 10 mm
• characterized by smoothness
• with direct contact (without paint)
• for force applied at a right angle (pull-off, not shear)
• at ambient temperature room level

Lifting capacity in real conditions – factors

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

• Gap (between the magnet and the metal), as even a tiny clearance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to varnish, rust or dirt).
• Force direction – remember that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Base massiveness – too thin sheet causes magnetic saturation, causing part of the power to be escaped to the other side.
• Steel grade – ideal substrate is high-permeability steel. Hardened steels may generate lower lifting capacity.
• Surface condition – ground elements ensure maximum contact, which improves force. Rough surfaces weaken the grip.
• Temperature – temperature increase results in weakening of induction. Check the maximum operating temperature for a given model.

* Holding force was checked on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate decreases the holding force.