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SM 25x250 [2xM8] / N42 - magnetic separator

magnetic separator

Catalog no 130293

GTIN: 5906301812869

Diameter Ø [±0,1 mm]

25 mm

Height [±0,1 mm]

250 mm

Weight

0.01 g

688.80 ZŁ with VAT / pcs + price for transport

560.00 ZŁ net + 23% VAT / pcs

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SM 25x250 [2xM8] / N42 - magnetic separator

Specification/characteristics SM 25x250 [2xM8] / N42 - magnetic separator

properties

values

Cat. no.

130293

GTIN

5906301812869

Production/Distribution

Dhit sp. z o.o.

Country of origin

Poland / China / Germany

Customs code

85059029

Diameter Ø

25 mm [±0,1 mm]

Height

250 mm [±0,1 mm]

Weight

0.01 g [±0,1 mm]

Manufacturing Tolerance

± 0.1 mm

Magnetic properties of material N42

properties

values

units

coercivity bHc ?

860-955

kA/m

coercivity bHc ?

10.8-12.0

kOe

energy density [Min. - Max.] ?

318-334

BH max KJ/m

energy density [Min. - Max.] ?

40-42

BH max MGOe

remenance Br [Min. - Max.] ?

12.9-13.2

kGs

remenance Br [Min. - Max.] ?

1290-1320

actual internal force iHc

≥ 955

kA/m

actual internal force iHc

≥ 12

kOe

max. temperature ?

≤ 80

°C

Physical properties of NdFeB

properties

values

units

Vickers hardness

≥550

Density

≥7.4

g/cm³

Curie Temperature TC

312 - 380

°C

Curie Temperature TF

593 - 716

°F

Specific resistance

150

μΩ⋅Cm

Bending strength

250

Mpa

Compressive strength

1000~1100

Mpa

Thermal expansion parallel (∥) to orientation (M)

(3-4) x 106

°C^-1

Thermal expansion perpendicular (⊥) to orientation (M)

-(1-3) x 10-6

°C^-1

Young's modulus

1.7 x 104

kg/mm²

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The magnetic separator, namely the magnetic roller, uses the force of neodymium magnets, placed in a construction made of stainless steel usually AISI304. As a result, it is possible to efficiently remove ferromagnetic particles from different substances. A key aspect of its operation is the use of repulsion of magnetic poles N and S, which causes magnetic substances to be targeted. The thickness of the magnet and its structure pitch affect the power and range of the separator's operation.

Generally speaking, magnetic separators serve to segregate ferromagnetic particles. If the cans are made from ferromagnetic materials, a magnetic separator will be effective. However, if the cans are made of non-ferromagnetic materials, such as aluminum, the separator will not effectively segregate them.

Yes, magnetic rollers are employed in the food industry to remove metallic contaminants, such as iron fragments or iron dust. Our rollers are built from acid-resistant steel, AISI 304, suitable for use in food.

Magnetic rollers, otherwise cylindrical magnets, find application in food production, metal separation as well as recycling. They help in eliminating iron dust in the course of the process of separating metals from other materials.

Our magnetic rollers are built with a neodymium magnet placed in a tube of stainless steel with a wall thickness of 1mm.

From both sides of the magnetic bar will be with M8 threaded openings, enabling simple mounting in machines or magnetic filter drawers. A "blind" version is also possible in manual separators.

In terms of features, magnetic bars stand out in terms of flux density, magnetic force lines and the field of the magnetic field. We produce them in two materials, N42 as well as N52.

Usually it is believed that the stronger the magnet, the better. But, the value of the magnet's power is based on the height of the used magnet and the quality of the material [N42] or [N52], as well as on the area of application and anticipated needs. The standard operating temperature of a magnetic bar is 80°C.

If the magnet is more flat, the magnetic force lines are short. On the other hand, in the case of a thicker magnet, the force lines are extended and extend over a greater distance.

For constructing the casings of magnetic separators - rollers, usually stainless steel is used, particularly types AISI 316, AISI 316L, and AISI 304.

In a saltwater environment, type AISI 316 steel is highly recommended thanks to its outstanding corrosion resistance.

Magnetic rollers stand out for their specific arrangement of poles and their ability to attract magnetic substances directly onto their surface, in contrast to other devices that often use complex filtration systems.

Technical designations and terms pertaining to magnetic separators include among others polarity, magnetic induction, magnet pitch, as well as the steel type applied.

Magnetic induction for a magnet on a roller is determined using a teslameter or a gaussmeter with a flat Hall-effect probe, aiming to find the highest magnetic field value close to the magnetic pole. The outcome is checked in a value table - the lowest is N30. All designations less than N27 or N25 suggest recycling that doesn't meet the standard - they are not suitable.

Neodymium magnetic rollers offer a range of benefits such as a very strong magnetic field, the ability to capture even the tiniest metal particles, and durability. However, some of the downsides may involve higher cost compared to other types of magnets and the need for regular maintenance.

For proper maintenance of neodymium magnetic rollers, it is recommended regularly cleaning them from deposits, avoiding high temperatures up to 80°C, and protecting them from moisture if the threads are not sealed – in ours, they are. The rollers feature waterproofing IP67, so if they are leaky, the magnets inside can rust and lose their power. Magnetic field measurements is recommended be carried out every two years. Care should be taken, as there is a risk of finger injury. If the protective tube is only 0.5 mm thick, it may wear out, which in turn could lead to problems with the magnetic rod seal and product contamination. The range of the roller is equal to its diameter: fi25mm gives an active range of about 25mm, while fi32 gives an active range of about 40mm.

A magnetic roller is a magnetic separator made from a neodymium magnet enclosed in a cylindrical stainless steel housing, which are used to remove metal contaminants from bulk and granular materials. They are applied in industries such as food processing, ceramics, and recycling, where the removal of iron metals and iron filings is essential.

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their tremendous magnetic power, neodymium magnets offer the following advantages:

They do not lose their magnetism, even after approximately 10 years – the decrease of strength is only ~1% (based on measurements),
They show exceptional resistance to demagnetization from external field exposure,
In other words, due to the glossy gold coating, the magnet obtains an professional appearance,
Magnetic induction on the surface of these magnets is impressively powerful,
They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
With the option for fine forming and personalized design, these magnets can be produced in multiple shapes and sizes, greatly improving design adaptation,
Significant impact in advanced technical fields – they are used in computer drives, rotating machines, diagnostic apparatus or even high-tech tools,
Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in small dimensions, which allows for use in small systems

Disadvantages of NdFeB magnets:

They can break when subjected to a sudden impact. If the magnets are exposed to physical collisions, we recommend in a metal holder. The steel housing, in the form of a holder, protects the magnet from damage and enhances its overall resistance,
High temperatures may significantly reduce the holding force of neodymium magnets. Typically, above 80°C, they experience permanent deterioration in performance (depending on height). To prevent this, we offer heat-resistant magnets marked [AH], capable of working up to 230°C, which makes them perfect for high-temperature use,
Magnets exposed to wet conditions can degrade. Therefore, for outdoor applications, we suggest waterproof types made of coated materials,
Using a cover – such as a magnetic holder – is advised due to the restrictions in manufacturing holes directly in the magnet,
Health risk related to magnet particles may arise, especially if swallowed, which is significant in the health of young users. Furthermore, minuscule fragments from these devices may hinder health screening when ingested,
High unit cost – neodymium magnets are costlier than other types of magnets (e.g., ferrite), which increases the cost of large-scale applications

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

The given holding capacity of the magnet corresponds to the highest holding force, determined under optimal conditions, namely:

with the use of low-carbon steel plate serving as a magnetic yoke
of a thickness of at least 10 mm
with a smooth surface
in conditions of no clearance
under perpendicular detachment force
under standard ambient temperature

Determinants of practical lifting force of a magnet

Practical lifting force is dependent on elements, listed from the most critical to the less significant:

Air gap between the magnet and the plate, as even a very small distance (e.g. 0.5 mm) causes a drop in lifting force of up to 50%.
Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Lifting capacity was determined with the use of a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under shearing force the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate reduces the lifting capacity.

Handle Neodymium Magnets with Caution

Keep neodymium magnets away from people with pacemakers.

Neodymium magnets produce strong magnetic fields that can interfere with the operation of a heart pacemaker. Even if the magnetic field does not affect the device, it can damage its components or deactivate the entire device.

Keep neodymium magnets away from TV, wallet, and computer HDD.

Strong fields generated by neodymium magnets can damage magnetic storage media such as floppy disks, credit cards, magnetic ID cards, cassette tapes, video tapes, or other similar devices. In addition, they can damage televisions, VCRs, computer monitors, and CRT displays. You should especially avoid placing neodymium magnets near electronic devices.

Never bring neodymium magnets close to a phone and GPS.

Magnetic fields generated by neodymium magnets interfere with compasses and magnetometers used in navigation, as well as internal compasses of smartphones and GPS devices.

Magnets are not toys, youngest should not play with them.

Not all neodymium magnets are toys, so do not let children play with them. In the case of small magnets, they can be swallowed and cause choking. In such cases, the only solution is to undergo surgery to remove the magnets, and otherwise, it can even lead to death.

Neodymium magnets can become demagnetized at high temperatures.

Although magnets have demonstrated their effectiveness up to 80°C or 175°F, the temperature can vary depending on the type, shape, and intended use of the specific magnet.

Neodymium magnets are primarily characterized by their significant internal force. They attract to each other, and any object that comes in their way will be affected.

If have a finger between or alternatively on the path of attracting magnets, there may be a large cut or even a fracture.

Comparing neodymium magnets to ferrite magnets (found in speakers), they are 10 times more powerful, and their strength can shock you.

To handle magnets properly, it is best to familiarize yourself with our information beforehand. This will help you avoid significant harm to your body and the magnets themselves.

Dust and powder from neodymium magnets are highly flammable.

Do not attempt to drill into neodymium magnets. Mechanical processing is also not recommended. Once crushed into fine powder or dust, this material becomes highly flammable.

Neodymium magnetic are extremely fragile, resulting in shattering.

In the event of a collision between two neodymium magnets, it can result in them getting chipped. They are coated with a shiny nickel plating similar to steel, but they are not as hard. In the case of a collision between two magnets, there can be a scattering of small sharp metal fragments in different directions. Protecting your eyes is essential.

If you have a nickel allergy, avoid contact with neodymium magnets.

Studies clearly indicate a small percentage of people who suffer from metal allergies such as nickel. An allergic reaction often manifests as skin redness and rash. If you have a nickel allergy, try wearing gloves or avoid direct contact with nickel-plated neodymium magnets.

Pay attention!

In order for you to know how powerful neodymium magnets are and why they are so dangerous, see the article - Dangerous very powerful neodymium magnets.