e-mail: bok@dhit.pl

neodymium magnets

We provide red color magnetic Nd2Fe14B - our offer. All magnesy neodymowe on our website are available for immediate purchase (check the list). See the magnet price list for more details see the magnet price list

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SM 32x250 [2xM8] / N42 - magnetic roller

magnetic separator

catalog number 130299

no reviews

diameter Ø

32 mm [±0,1 mm]


250 mm [±0,1 mm]

max. temperature

≤ 80 °C

750.30 PLN gross price (including VAT) / pcs +

610.00 PLN net price + 23% VAT / pcs

bulk discounts:

need more quantity?

price from 1 pcs
610.00 PLN
750.30 PLN
price from 4 pcs
579.50 PLN
712.78 PLN
price from 8 pcs
549.00 PLN
675.27 PLN

Want to bargain?

Give us a call tel: +48 22 499 98 98 or get in touch through form on the contact page. You can check the strength and the shape of neodymium magnet in our magnetic calculator magnetic mass calculator

Orders placed by 2:00 PM will be shipped on the same business day.

Specification: magnetic separator 32x250 [2xM8] / N42

Characteristics: magnetic separator 32x250 [2xM8] / N42
catalog number
production / distribution
Dhit sp. z o.o.
country of origin
Poland / China / Germany
customs code
diameter Ø
32 mm [±0,1 mm]
250 mm [±0,1 mm]
max. temperature ?
≤ 80 °C
1240.00 g
execution tolerance
± 0.1 mm
rodzaj materiału
AISI 304 - bezpieczna dla żywności
rodzaj magnesów
NdFeB N42
ilość gwintów
2x [M8] wewnętrzne
obwodowa - 9 nadbiegunników
indukcja magnetyczna
~ 8 000 Gauss [±5%]
max. temp. pracy
poniżej ≤ 80°C
grubość rury osłonowej
1 mm

Magnetic properties of the material N42

material characteristics N42
remenance Br [Min. - Max.] ?
remenance Br [Min. - Max.] ?
coercivity bHc ?
coercivity bHc ?
actual internal force iHc
≥ 12
actual internal force iHc
≥ 955
energy density [Min. - Max.]
BH max MGOe
energy density [Min. - Max.]
BH max KJ/m
max. temperature
≤ 80

Physical properties of sintered neodymium magnets Nd2Fe14B

Physical properties of sintered neodymium magnets Nd2Fe14B
Vickers hardness
Curie Temperature TC
312 - 380
Curie Temperature TF
593 - 716
Specific resistance
Bending strength
Compressive strength
Thermal expansion parallel (∥) to orientation (M)
(3-4) x 106
Thermal expansion perpendicular (⊥) to orientation (M)
-(1-3) x 10-6
Young's modulus
1.7 x 104
The main mechanism of the magnetic separator is the use of neodymium magnets, which are embedded in a casing made of stainless steel usually AISI304. Due to this, it is possible to precisely segregate ferromagnetic particles from other materials. A key aspect of its operation is the use of repulsion of magnetic poles N and S, which causes magnetic substances to be collected. The thickness of the embedded magnet and its structure pitch affect the power and range of the separator's operation.
Generally speaking, magnetic separators are designed to segregate ferromagnetic elements. If the cans are ferromagnetic, the separator will be able to separate them. However, if the cans are made of non-ferromagnetic materials, such as aluminum, the separator will not effectively segregate them.
Yes, magnetic rollers find application in the food industry to clear metallic contaminants, for example iron fragments or iron dust. Our rods are made from durable acid-resistant steel, AISI 304, suitable for contact with food.
Magnetic rollers, often called cylindrical magnets, are employed in food production, metal separation as well as recycling. They help in eliminating iron dust during the process of separating metals from other materials.
Our magnetic rollers are composed of a neodymium magnet anchored in a stainless steel tube cylinder made of stainless steel with a wall thickness of 1mm.
Both ends of the magnetic bar will be with M8 threaded holes - 18 mm, which enables easy installation in machines or magnetic filter drawers. A "blind" version is also possible in manual separators.
In terms of forces, magnetic bars stand out in terms of magnetic force lines, flux density and the field of the magnetic field. We produce them in two materials, N42 as well as N52.
Often it is believed that the stronger the magnet, the more efficient it is. Nevertheless, the effectiveness 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 anticipated needs. The standard operating temperature of a magnetic bar is 80°C.
In the case where the magnet is thin, the magnetic force lines are short. Otherwise, in the case of a thicker magnet, the force lines are longer and reach further.
For constructing the casings of magnetic separators - rollers, most often stainless steel is employed, especially types AISI 316, AISI 316L, and AISI 304.
In a salt water contact, AISI 316 steel is recommended thanks to its excellent anti-corrosion properties.
Magnetic bars stand out for their specific arrangement of poles and their ability to attract magnetic particles directly onto their surface, in contrast to other separators that may utilize complex filtration systems.
Technical designations and terms related to magnetic separators include among others magnet pitch, polarity, and magnetic induction, as well as the steel type applied.
Magnetic induction for a roller is measured using a teslameter or a gaussmeter with a flat Hall-effect probe, seeking the highest magnetic field value near the magnetic pole. The outcome is checked in a value table - the lowest is N30. All designations below N27 or N25 suggest recycling that falls below the standard - they are not suitable.
Neodymium magnetic rollers offer many advantages, including excellent separation efficiency, strong magnetic field, and durability. On the other hand, among the drawbacks, one can mention the need for regular cleaning, higher cost, and potential installation challenges.
To properly maintain of neodymium magnetic rollers, it is advised {to clean them regularly from contaminants, avoid extremal temperatures up to 80°C, and to clean them regularly, avoiding temperatures up to 80°C. The rollers have an IP67 waterproof rating, so if they are not sealed, the magnets inside may oxidize and lose their strength. Roller inspections are advised to be conducted once every 24 months. Care should be taken as there is a possibility of finger injury. If the protective tube is only 0.5 mm thick, it can be worn down, which, in turn, can result in issues with the magnetic rod becoming unsealed and product contamination. The effective operating range of the roller equals its diameter, fi25mm is approximately 25mm active range, while fi32 is about 40mm.

Compilation of suggested goods

Advantages as well as disadvantages of neodymium magnets NdFeB.

Apart from immense power, neodymium magnets have the following advantages:

  • They do not lose their strength (of the magnet). After approximately 10 years, their strength decreases by only ~1% (theoretically),
  • They are exceptionally resistant to demagnetization caused by an external magnetic field,
  • By applying a shiny coating of nickel, gold, or silver, the element gains an aesthetic appearance,
  • They exhibit very high magnetic induction on the surface of the magnet,
  • By using an appropriate combination of materials, they can achieve high thermal resistance, allowing them to operate at temperatures up to 230°C and above...
  • Due to the option of accurate forming and adaptation to individual needs – neodymium magnets can be produced in many variants of shapes and sizes, which enhances their versatility in applications.
  • Wide application in modern technologies – find application in HDD drives, electric motors, medical devices or other modern machines.

Disadvantages of neodymium magnets:

  • They can break when subjected to a powerful impact. If the magnets are exposed to impacts, we recommend using magnets in a steel housing. The steel housing in the form of a holder protects the magnet from impacts and at the same time increases its overall strength,
  • They lose power at high temperatures. Most neodymium magnets experience permanent loss of strength when heated above 80°C (depending on the shape and height). However, we also offer special magnets with high temperature resistance, up to 230°C,
  • They rust in a humid environment. For outdoor use, we recommend using waterproof magnets, such as those made of rubber or plastic,
  • The use of a cover or a magnetic holder is recommended due to the limited possibilities of manufacturing threads or complex shapes in the magnet
  • Health risk arising from small pieces of magnets can be dangerous, in case of ingestion, which is particularly important in the context of child safety. Additionally, miniscule components of these products are able to complicate diagnosis in case of swallowing.

Handle with Care: Neodymium Magnets

Dust and powder from neodymium magnets are flammable.

Avoid drilling or mechanical processing of neodymium magnets. If the magnet is crushed into fine powder or dust, it becomes highly flammable.

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

Remember that neodymium magnets are not toys. Be cautious and make sure no child plays with them. In the case of swallowing multiple magnets simultaneously, they can attract to each other through the intestinal walls. In the worst case scenario, this can lead to death.

Neodymium magnetic are noted for being fragile, which can cause them to shatter.

Neodymium magnets are characterized by significant fragility. Neodymium magnets are made of metal and coated with a shiny nickel surface, but they are not as hard as steel. In the event of a collision between two magnets, there may be a scattering of fragments in different directions. Protecting your eyes is crucial in such a situation.

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, try wearing gloves or avoid direct contact with nickel-plated neodymium magnets.

Neodymium magnets are not recommended for 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.

Neodymium magnets can become demagnetized 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.

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

Familiarize yourself with our information to correctly handle these magnets and avoid significant injuries to your body and prevent damage to the magnets.

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

Strong magnetic fields emitted by neodymium magnets can destroy magnetic storage media such as floppy disks, credit cards, magnetic ID cards, cassette tapes, video tapes, or other devices. In addition, they can damage televisions, VCRs, computer monitors, and CRT displays. Avoid placing neodymium magnets in close proximity to electronic devices.

Do not bring neodymium magnets close to GPS and smartphones.

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.

It is crucial not to allow the magnets to pinch together uncontrollably or place your fingers in their path as they attract to each other.

Magnets attract each other within a distance of several to around 10 cm from each other. Remember not to place fingers between magnets or in their path when they attract. Depending on how massive the neodymium magnets are, they can lead to a cut or alternatively a fracture.

So that know how strong neodymium magnets are and why they are so dangerous, read the article - Dangerous very powerful neodymium magnets.

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e-mail: bok@dhit.pl

tel: +48 888 99 98 98