BM 550x180x70 [4x M8] - magnetic beam

Strengths and weaknesses of neodymium magnets.

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

• Their magnetic field remains stable, and after approximately 10 years it drops only by ~1% (theoretically),
• They show high resistance to demagnetization induced by presence of other magnetic fields,
• In other words, due to the glossy layer of nickel, the element gains a professional look,
• Magnetic induction on the working part of the magnet remains exceptional,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• Considering the ability of accurate shaping and customization to specialized projects, NdFeB magnets can be modeled in a wide range of geometric configurations, which amplifies use scope,
• Fundamental importance in modern technologies – they serve a role in magnetic memories, electric drive systems, medical equipment, also complex engineering applications.
• Thanks to their power density, small magnets offer high operating force, in miniature format,

Disadvantages of NdFeB magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only protects the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets suffer 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
• We recommend casing - magnetic mount, due to difficulties in creating nuts inside the magnet and complex forms.
• Possible danger to health – tiny shards of magnets can be dangerous, if swallowed, which gains importance in the aspect of protecting the youngest. Furthermore, tiny parts of these magnets can be problematic in diagnostics medical when they are in the body.
• Due to complex production process, their price is higher than average,

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

The lifting capacity listed is a result of laboratory testing executed under standard conditions:

• using a base made of high-permeability steel, functioning as a circuit closing element
• possessing a thickness of min. 10 mm to ensure full flux closure
• with an ground contact surface
• without any clearance between the magnet and steel
• during pulling in a direction vertical to the mounting surface
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

Real force is affected by specific conditions, such as (from most important):

• Gap between magnet and steel – every millimeter of separation (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to detachment vertically. When slipping, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Steel type – mild steel attracts best. Alloy admixtures reduce magnetic properties and holding force.
• Surface condition – smooth surfaces ensure maximum contact, which increases field saturation. Rough surfaces weaken the grip.
• Temperature – heating the magnet results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity was assessed by applying a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet and the plate decreases the lifting capacity.