NCM 30x13.5x5 / N38 - channel magnetic holder

Pros as well as cons of rare earth magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They virtually do not lose strength, because even after ten years the performance loss is only ~1% (in laboratory conditions),
• Magnets perfectly defend themselves against loss of magnetization caused by foreign field sources,
• A magnet with a smooth silver surface looks better,
• Magnets have very high magnetic induction on the working surface,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Due to the ability of precise molding and adaptation to individualized projects, magnetic components can be produced in a broad palette of forms and dimensions, which increases their versatility,
• Wide application in high-tech industry – they are used in mass storage devices, brushless drives, precision medical tools, and industrial machines.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Drawbacks and weaknesses of neodymium magnets: application proposals

• They are fragile upon heavy impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only shields the magnet but also improves its resistance to damage
• Neodymium magnets decrease their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in creating nuts and complicated shapes in magnets, we recommend using cover - magnetic mount.
• Possible danger related to microscopic parts of magnets pose a threat, if swallowed, which gains importance in the context of child health protection. It is also worth noting that small elements of these products can be problematic in diagnostics medical in case of swallowing.
• Due to complex production process, their price exceeds standard values,

Maximum lifting capacity of the magnet – what contributes to it?

The declared magnet strength concerns the maximum value, recorded under ideal test conditions, specifically:

• on a block made of structural steel, perfectly concentrating the magnetic field
• possessing a thickness of min. 10 mm to ensure full flux closure
• characterized by lack of roughness
• under conditions of gap-free contact (metal-to-metal)
• for force applied at a right angle (pull-off, not shear)
• at standard ambient temperature

Determinants of practical lifting force of a magnet

Effective lifting capacity impacted by working environment parameters, mainly (from most important):

• Air gap (betwixt the magnet and the plate), because even a very small distance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to paint, rust or dirt).
• Force direction – declared lifting capacity refers to pulling vertically. When slipping, the magnet holds much less (often approx. 20-30% of nominal force).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Steel grade – ideal substrate is pure iron steel. Hardened steels may generate lower lifting capacity.
• Surface quality – the smoother and more polished the surface, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Temperature – temperature increase results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity was determined using a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under parallel forces the holding force is lower. In addition, even a slight gap {between} the magnet and the plate reduces the load capacity.