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SM 25x400 [2xM8] / N42 - magnetic separator

magnetic separator

Catalog no 130365

GTIN: 5906301813392

Diameter Ø [±0,1 mm]

25 mm

Height [±0,1 mm]

400 mm

Weight

0.01 g

1131.60 ZŁ with VAT / pcs + price for transport

920.00 ZŁ net + 23% VAT / pcs

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SM 25x400 [2xM8] / N42 - magnetic separator

Specification/characteristics SM 25x400 [2xM8] / N42 - magnetic separator

properties

values

Cat. no.

130365

GTIN

5906301813392

Production/Distribution

Dhit sp. z o.o.

Country of origin

Poland / China / Germany

Customs code

85059029

Diameter Ø

25 mm [±0,1 mm]

Height

400 mm [±0,1 mm]

Weight

0.01 g [±0,1 mm]

Manufacturing Tolerance

± 0.1 mm

Magnetic properties of material N42

properties

values

units

remenance Br [Min. - Max.] ?

12.9-13.2

kGs

remenance Br [Min. - Max.] ?

1290-1320

coercivity bHc ?

10.8-12.0

kOe

coercivity bHc ?

860-955

kA/m

actual internal force iHc

≥ 12

kOe

actual internal force iHc

≥ 955

kA/m

energy density [Min. - Max.] ?

40-42

BH max MGOe

energy density [Min. - Max.] ?

318-334

BH max KJ/m

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 power of neodymium magnets, placed in a construction made of stainless steel usually AISI304. In this way, it is possible to precisely separate ferromagnetic elements from other materials. An important element of its operation is the repulsion of magnetic poles N and S, which enables magnetic substances to be targeted. The thickness of the embedded magnet and its structure pitch affect the range and strength of the separator's operation.

Generally speaking, magnetic separators are used to extract ferromagnetic particles. If the cans are made of ferromagnetic materials, the separator will effectively segregate them. However, if the cans are made of non-ferromagnetic materials, such as aluminum, the separator will not be able to separate them.

Yes, magnetic rollers are used in the food industry to remove metallic contaminants, for example iron fragments or iron dust. Our rollers are constructed from durable acid-resistant steel, EN 1.4301, approved for use in food.

Magnetic rollers, often called cylindrical magnets, are employed in metal separation, food production as well as waste processing. They help in removing iron dust during the process of separating metals from other materials.

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

Both ends of the magnetic bar will be with M8 threaded holes - 18 mm, allowing for easy installation in machines or magnetic filter drawers. A "blind" version is also possible in manual separators.

In terms of magnetic properties, magnetic bars differ in terms of magnetic force lines, flux density and the field of the magnetic field. We produce them in materials, N42 and N52.

Generally it is believed that the greater the magnet's power, the more efficient it is. However, the strength of the magnet's power is dependent 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 expected needs. The standard operating temperature of a magnetic bar is 80°C.

If the magnet is thin, the magnetic force lines will be short. By contrast, when the magnet is thick, the force lines will be extended and extend over a greater distance.

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

In a saltwater contact, type AISI 316 steel exhibits the best resistance due to its exceptional corrosion resistance.

Magnetic bars are characterized by their unique configuration of poles and their ability to attract magnetic particles directly onto their surface, in contrast to other devices that often use more complicated filtration systems.

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

Magnetic induction for a magnet on a roller is measured 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 result is checked in a value table - the lowest is N30. All designations below N27 or N25 suggest recycling that doesn't meet the standard - they are not suitable.

Neodymium magnetic bars offer a range of benefits such as excellent separation efficiency, strong magnetic field, and durability. However, some of the downsides may involve the need for regular cleaning, higher cost, and potential installation challenges.

For proper maintenance of neodymium magnetic rollers, it is recommended they should be regularly cleaned, avoiding temperatures above 80 degrees. The rollers our rollers have waterproofing IP67, so if they are leaky, the magnets inside can rust and weaken. Magnetic field measurements is recommended be carried out once every 24 months. Caution should be taken during use, as it’s possible 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 corresponds 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, used for separating ferromagnetic contaminants from raw materials. They are used in the food industry, recycling, and plastic processing, where the removal of iron metals and iron filings is essential.

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their pulling strength, neodymium magnets provide the following advantages:

Their strength is durable, and after around ten years, it drops only by ~1% (according to research),
They are very resistant to demagnetization caused by external field interference,
The use of a decorative silver surface provides a refined finish,
They have exceptional magnetic induction on the surface of the magnet,
Neodymium magnets are known for exceptionally strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the geometry),
With the option for customized forming and precise design, these magnets can be produced in numerous shapes and sizes, greatly improving design adaptation,
Wide application in new technology industries – they are used in HDDs, electric motors, clinical machines along with high-tech tools,
Relatively small size with high magnetic force – neodymium magnets offer strong power in small dimensions, which makes them ideal in small systems

Disadvantages of magnetic elements:

They are prone to breaking when subjected to a heavy impact. If the magnets are exposed to physical collisions, they should be placed in a protective case. The steel housing, in the form of a holder, protects the magnet from damage and strengthens its overall robustness,
They lose power at elevated temperatures. Most neodymium magnets experience permanent degradation in strength when heated above 80°C (depending on the dimensions and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
Due to corrosion risk in humid conditions, it is wise to use sealed magnets made of protective material for outdoor use,
The use of a protective casing or external holder is recommended, since machining threads in neodymium magnets is not feasible,
Potential hazard due to small fragments may arise, especially if swallowed, which is important in the protection of children. Additionally, minuscule fragments from these products can interfere with diagnostics if inside the body,
High unit cost – neodymium magnets are costlier than other types of magnets (e.g., ferrite), which can restrict large-scale applications

Magnetic strength at its maximum – what it depends on?

The given strength of the magnet corresponds to the optimal strength, assessed in the best circumstances, specifically:

with mild steel, serving as a magnetic flux conductor
with a thickness of minimum 10 mm
with a refined outer layer
with zero air gap
with vertical force applied
at room temperature

What influences lifting capacity in practice

In practice, the holding capacity of a magnet is affected by the following aspects, from crucial to less important:

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 by applying a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet and the plate reduces the holding force.

Handle Neodymium Magnets Carefully

Neodymium magnets can attract to each other, pinch the skin, and cause significant swellings.

Magnets will bounce and clash together within a radius of several to around 10 cm from each other.

Neodymium magnets should not be near people with pacemakers.

Neodymium magnets generate strong magnetic fields. As a result, they interfere with the operation of a pacemaker. This is because many of these devices are equipped with a function that deactivates the device in a magnetic field.

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

Neodymium magnets are not toys. Do not allow children to play with them. Small magnets can pose a serious choking hazard. If multiple magnets are swallowed, they can attract to each other through the intestinal walls, causing significant injuries, and even death.

Dust and powder from neodymium magnets are flammable.

Avoid drilling or mechanical processing of neodymium magnets. Once crushed into fine powder or dust, this material becomes highly flammable.

Neodymium magnets can demagnetize at high temperatures.

Although magnets have shown to retain their effectiveness up to 80°C or 175°F, this temperature may vary depending on the type of material, shape, and intended use of the magnet.

Never bring neodymium magnets close to a phone and GPS.

Magnetic fields interfere with compasses and magnetometers used in navigation for air and sea transport, as well as internal compasses of smartphones and GPS devices.

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

Studies show a small percentage of people have allergies to certain metals, including nickel. An allergic reaction often manifests as skin redness and rash. If you have a nickel allergy, you can try wearing gloves or simply avoid direct contact with nickel-plated neodymium magnets.

Do not place neodymium magnets near a computer HDD, TV, and wallet.

Magnetic 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.

Neodymium magnetic are particularly delicate, resulting in shattering.

In the event of a collision between two neodymium magnets, it can result in them getting chipped. Despite being made of metal as well as coated with a shiny nickel plating, they are not as hard as steel. At the moment of connection between the magnets, small sharp metal fragments can be propelled in various directions at high speed. Eye protection is recommended.

Neodymium magnets are among the strongest magnets on Earth. The surprising force they generate between each other can shock you.

Read the information on our website on how to properly utilize neodymium magnets and avoid significant harm to your body and unintentional damage to the magnets.

Safety precautions!

In order to show why neodymium magnets are so dangerous, read the article - How very dangerous are powerful neodymium magnets?.