BM 650x180x70 [4x M8] - magnetic beam

Advantages as well as disadvantages of NdFeB magnets.

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

• They do not lose power, even during around 10 years – the drop in strength is only ~1% (theoretically),
• They maintain their magnetic properties even under strong external field,
• In other words, due to the metallic surface of nickel, the element gains visual value,
• They feature high magnetic induction at the operating surface, which increases their power,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, allowing for action at temperatures approaching 230°C and above...
• In view of the option of precise forming and customization to unique needs, NdFeB magnets can be manufactured in a variety of forms and dimensions, which expands the range of possible applications,
• Universal use in modern industrial fields – they serve a role in computer drives, brushless drives, advanced medical instruments, and technologically advanced constructions.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

What to avoid - cons of neodymium magnets and ways of using them

• At very strong impacts they can crack, therefore we advise placing them in strong housings. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their power 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
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Limited ability of making nuts in the magnet and complex forms - recommended is cover - magnet mounting.
• Health risk resulting from small fragments of magnets are risky, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small elements of these magnets can be problematic in diagnostics medical after entering the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which hinders application in large quantities

Maximum magnetic pulling force – what it depends on?

Holding force of 0 kg is a theoretical maximum value conducted under standard conditions:

• using a sheet made of low-carbon steel, serving as a magnetic yoke
• possessing a massiveness of min. 10 mm to avoid saturation
• characterized by even structure
• under conditions of gap-free contact (metal-to-metal)
• during detachment in a direction vertical to the plane
• in temp. approx. 20°C

Lifting capacity in real conditions – factors

Real force is affected by specific conditions, including (from priority):

• Air gap (betwixt the magnet and the plate), since even a very small clearance (e.g. 0.5 mm) results in a drastic drop in force by up to 50% (this also applies to paint, rust or dirt).
• Load vector – highest force is reached only during perpendicular pulling. The force required to slide of the magnet along the plate is usually many times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Steel type – mild steel attracts best. Alloy steels decrease magnetic properties and lifting capacity.
• Surface finish – ideal contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Thermal environment – temperature increase causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was measured with the use of a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under parallel forces the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet’s surface and the plate reduces the load capacity.