SM 25x250 [2xM8] / N52 - magnetic separator

Pros and cons of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They do not lose power, even during approximately 10 years – the drop in strength is only ~1% (theoretically),
• They feature excellent resistance to weakening of magnetic properties due to external fields,
• In other words, due to the glossy layer of silver, the element gains a professional look,
• Neodymium magnets generate maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to freedom in shaping and the ability to customize to client solutions,
• Universal use in advanced technology sectors – they are utilized in magnetic memories, electromotive mechanisms, medical equipment, as well as industrial machines.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets and proposals for their use:

• At strong impacts they can break, therefore we advise placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic mount, due to difficulties in realizing threads inside the magnet and complex forms.
• Potential hazard to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Additionally, tiny parts of these products can 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

Maximum magnetic pulling force – what contributes to it?

The load parameter shown represents the limit force, measured under ideal test conditions, meaning:

• with the contact of a sheet made of special test steel, ensuring maximum field concentration
• possessing a thickness of min. 10 mm to avoid saturation
• with an polished contact surface
• under conditions of ideal adhesion (surface-to-surface)
• under perpendicular force direction (90-degree angle)
• at room temperature

Practical lifting capacity: influencing factors

It is worth knowing that the application force may be lower subject to elements below, starting with the most relevant:

• Gap (betwixt the magnet and the plate), since even a tiny distance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to paint, rust or dirt).
• Force direction – catalog parameter refers to detachment vertically. When applying parallel force, the magnet holds significantly lower power (often approx. 20-30% of nominal force).
• Plate thickness – insufficiently thick sheet does not close the flux, causing part of the flux to be lost to the other side.
• Steel type – mild steel gives the best results. Alloy steels decrease magnetic properties and lifting capacity.
• Base smoothness – the smoother and more polished the plate, the larger the contact zone and stronger the hold. Roughness acts like micro-gaps.
• Temperature – temperature increase causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity was determined using a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular detachment force, whereas under attempts to slide the magnet the holding force is lower. Moreover, even a slight gap {between} the magnet and the plate lowers the holding force.