UMH 16x5x32 [M4] / N38 - magnetic holder with hook

Strengths as well as weaknesses of NdFeB magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• Their strength remains stable, and after approximately ten years it decreases only by ~1% (according to research),
• Neodymium magnets are highly resistant to loss of magnetic properties caused by external magnetic fields,
• A magnet with a metallic nickel surface looks better,
• Magnetic induction on the surface of the magnet is maximum,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Possibility of accurate forming and adjusting to atypical conditions,
• Significant place in modern industrial fields – they find application in computer drives, motor assemblies, medical equipment, and industrial machines.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

What to avoid - cons of neodymium magnets: tips and applications.

• To avoid cracks under impact, we recommend using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• Due to limitations in creating nuts and complicated shapes in magnets, we propose using casing - magnetic mechanism.
• Health risk related to microscopic parts of magnets are risky, in case of ingestion, which gains importance in the context of child safety. Furthermore, tiny parts of these magnets are able to disrupt the diagnostic process medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Optimal lifting capacity of a neodymium magnet – what affects it?

The specified lifting capacity refers to the maximum value, obtained under optimal environment, specifically:

• on a block made of structural steel, perfectly concentrating the magnetic flux
• possessing a massiveness of minimum 10 mm to ensure full flux closure
• with a plane perfectly flat
• with zero gap (no impurities)
• during pulling in a direction vertical to the mounting surface
• in neutral thermal conditions

Impact of factors on magnetic holding capacity in practice

In practice, the actual holding force results from a number of factors, ranked from most significant:

• Distance (between the magnet and the metal), as even a very small distance (e.g. 0.5 mm) leads to a decrease in force by up to 50% (this also applies to paint, rust or dirt).
• Force direction – note that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Wall thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of generating force.
• Material composition – different alloys reacts the same. High carbon content weaken the interaction with the magnet.
• Surface finish – full contact is obtained only on polished steel. Rough texture reduce the real contact area, reducing force.
• Temperature influence – high temperature weakens pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under parallel forces the holding force is lower. Additionally, even a minimal clearance {between} the magnet’s surface and the plate decreases the lifting capacity.