BM 320x180x70 [4x M8] - magnetic beam

Strengths as well as weaknesses of neodymium magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They retain magnetic properties for nearly ten years – the drop is just ~1% (according to analyses),
• Neodymium magnets are characterized by remarkably resistant to magnetic field loss caused by external magnetic fields,
• A magnet with a metallic gold surface is more attractive,
• The surface of neodymium magnets generates a unique magnetic field – this is a key feature,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures approaching 230°C and above...
• Thanks to the potential of free molding and customization to individualized solutions, magnetic components can be manufactured in a wide range of forms and dimensions, which makes them more universal,
• Universal use in electronics industry – they are utilized in magnetic memories, electromotive mechanisms, diagnostic systems, as well as other advanced devices.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of neodymium magnets:

• At very strong impacts they can crack, therefore we advise placing them in special holders. 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 power. 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 corrode. Therefore when using outdoors, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Limited ability of making threads in the magnet and complicated forms - preferred is casing - magnet mounting.
• Potential hazard related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child health protection. Additionally, tiny parts of these magnets 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

Highest magnetic holding force – what affects it?

The specified lifting capacity refers to the peak performance, recorded under ideal test conditions, namely:

• on a block made of structural steel, perfectly concentrating the magnetic field
• whose thickness equals approx. 10 mm
• characterized by lack of roughness
• with direct contact (no coatings)
• during pulling in a direction vertical to the mounting surface
• at standard ambient temperature

Practical aspects of lifting capacity – factors

During everyday use, the real power is determined by a number of factors, listed from crucial:

• Space between magnet and steel – every millimeter of separation (caused e.g. by veneer or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to pulling vertically. When applying parallel force, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Steel grade – the best choice is high-permeability steel. Hardened steels may attract less.
• Base smoothness – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Thermal environment – heating the magnet causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity testing was conducted on plates with a smooth surface of suitable thickness, under perpendicular forces, however under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet’s surface and the plate decreases the lifting capacity.