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neodymium magnets

We offer yellow color magnets Nd2Fe14B - our proposal. Practically all magnesy neodymowe on our website are available for immediate purchase (check the list). See the magnet price list for more details check the magnet price list

Magnets for water searching F400 GOLD

Where to buy strong neodymium magnet? Holders with magnets in airtight, solid steel enclosure are perfect for use in difficult weather, including during snow and rain see...

magnets with holders

Holders with magnets can be used to enhance production processes, underwater discoveries, or searching for meteorites from gold check...

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Product available shipping tomorrow!

SM 25x125 [2xM8] / N42 - magnetic roller

magnetic separator

catalog number 130288

no reviews

diameter Ø

25 mm

height

125 mm

max. temperature

≤ 80 °C

319.80 PLN gross price (including VAT) / pcs +

260.00 PLN net price + 23% VAT / pcs

bulk discounts:

need more quantity?
price from 1 pcs
260.00 PLN
319.80 PLN
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price from 17 pcs
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Do you have a dilemma in choosing?

Give us a call tel: +48 22 499 98 98 or get in touch via 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 25x125 [2xM8] / N42

Characteristics: magnetic separator 25x125 [2xM8] / N42
Properties
Values
production / distribution
Dhit sp. z o.o.
country of origin
Poland / China / Germany
customs code
85059029
diameter Ø ?
25 mm
height ?
125 mm
max. temperature ?
≤ 80 °C
weight
0.01 g
execution tolerance
± 0.1 mm
rodzaj materiału
AISI 304 - bezpieczna dla żywności
rodzaj magnesów
NdFeB N42
ilość gwintów
2x [M8] wewnętrzne
biegunowość
obwodowa - 4 nabiegunniki
indukcja magnetyczna
~ 6 500 Gauss [±5%]
max. temp. pracy
poniżej ≤ 80°C
grubość rury osłonowej
1 mm

Magnetic properties of the material N42

material characteristics N42
Properties
Values
units
remenance Br [Min. - Max.] ?
12.9-13.2
kGs
remenance Br [Min. - Max.] ?
1290-1320
T
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 sintered neodymium magnets Nd2Fe14B

Physical properties of sintered neodymium magnets Nd2Fe14B
Properties
Values
units
Vickers hardness
≥550
Hv
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
The magnetic separator, namely the magnetic roller, uses the power of neodymium magnets, which are welded in a construction made of stainless steel mostly AISI304. As a result, it is possible to effectively segregate ferromagnetic particles from different substances. An important element of its operation is the use of repulsion of N and S poles of neodymium magnets, which causes magnetic substances to be targeted. The thickness of the embedded magnet and its structure pitch determine 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 are used in the food industry for the elimination of metallic contaminants, such as iron fragments or iron dust. Our rollers are made from acid-resistant steel, EN 1.4301, suitable for contact with food.
Magnetic rollers, often called magnetic separators, are employed in metal separation, food production as well as recycling. They help in removing iron dust during the process of separating metals from other materials.
Our magnetic rollers are built with neodymium magnets embedded 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 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 differ in terms of flux density, magnetic force lines and the area of operation of the magnetic field. We produce them in materials, N42 as well as N52.
Often it is believed that the stronger the magnet, the more effective. However, the effectiveness of the magnet's power depends on the height of the used magnet and the quality of the material [N42] or [N52], as well as on the area of use and anticipated needs. The standard operating temperature of a magnetic bar is 80°C.
When the magnet is thin, the magnetic force lines are more compressed. On the other hand, when the magnet is thick, the force lines are longer and reach further.
For making the casings of magnetic separators - rollers, usually stainless steel is used, particularly types AISI 316, AISI 316L, and AISI 304.
In a saltwater contact, type AISI 316 steel is recommended due to its excellent anti-corrosion properties.
Magnetic bars stand out for their unique configuration of poles and their ability to attract magnetic substances directly onto their surface, in contrast to other devices that often use more complicated filtration systems.
Technical designations and terms related to magnetic separators comprise 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, 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 indicate recycling that falls below the standard - they are not suitable.
Neodymium magnetic bars offer a range of benefits such as higher attracting power, longer lifespan, and effectiveness in separating fine metal particles. On the other hand, among the drawbacks, one can mention higher cost compared to other types of magnets and the need for regular maintenance.
To properly maintain of neodymium magnetic rollers, it is suggested {to clean them regularly from deposits, avoid extremal temperatures up to 80°C, and protect them from moisture if the threads are not sealed - in our case. The rollers our rollers have an IP67 waterproof rating, so if they are not sealed, the magnets inside may rust and lose their strength. Roller inspections are advised to be conducted 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 can wear out, which, in turn, can result in issues with the magnetic rod becoming unsealed and product contamination. The Roller operating range equals its diameter, fi25mm is approximately 25mm active range, while fi32 is about 40mm.

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Advantages and disadvantages of neodymium magnets NdFeB.

In addition to immense strength, neodymium magnets have the following advantages:

  • They do not lose their strength (of the magnet). After approximately 10 years, their power decreases by only ~1% (theoretically),
  • They are highly resistant to demagnetization by external magnetic sources,
  • Thanks to the shiny finish and nickel, gold, or silver coating, they have an aesthetic appearance,
  • They have exceptionally high magnetic induction on the surface of the magnet,
  • By using an appropriate combination of materials, they can achieve significant thermal resistance, allowing them to operate at temperatures up to 230°C and above...
  • Due to the option of accurate forming or adaptation to individual needs – neodymium magnets can be produced in a wide range of shapes and sizes, which enhances their versatility in applications.
  • Key role in modern technologies – are utilized in computer drives, electric motors, medical apparatus and other highly developed apparatuses.

Disadvantages of neodymium magnets:

  • They are prone to breaking as they are extremely fragile when subjected to a strong impact. If the magnets are exposed to impacts, we recommend using magnets in a metal holder. The steel housing in the form of a holder protects the magnet from impacts and simultaneously increases its overall strength,
  • They lose strength at high temperatures. Most neodymium magnets experience permanent loss of strength when heated above 80°C (depending on the form and height). However, we also offer special magnets with high temperature resistance, up to 230°C,
  • Magnets exposed to a humid environment can corrode. Therefore, when using them outdoors, we recommend using waterproof magnets made of rubber, plastic, or other moisture-resistant materials,
  • Limited ability to create threads or complex shapes in the magnet - the use of a housing is recommended - magnetic holder
  • Potential hazard associated with microscopic parts of magnets are risky, if swallowed, which is crucial in the aspect of protecting young children. Additionally, miniscule components of these devices have the potential to hinder the diagnostic process when they are in the body.

Be Cautious with Neodymium Magnets

The magnet is coated with nickel - be careful if you have an allergy.

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.

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.

Keep neodymium magnets away from 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.

You should keep neodymium magnets at a safe distance from the wallet, computer, and TV.

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. Avoid placing neodymium magnets in close proximity to electronic devices.

Magnets will attract to each other, so remember not to allow them to pinch together without control or place your fingers in their path.

If joining of neodymium magnets is not under control, at that time they may crumble and crack. You can't approach them to each other. At a distance less than 10 cm you should have them very strongly.

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.

Magnets made of neodymium are delicate and can easily break as well as shatter.

Neodymium magnets are characterized by significant fragility. Magnets made of neodymium are made of metal and coated with a shiny nickel, but they are not as durable as steel. At the moment of collision between the magnets, sharp metal fragments can be dispersed in different directions.

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.

  Magnets should not be treated as toys. Therefore, it is not recommended for youngest children to have access to them.

Not all neodymium magnets are toys, so do not let children play with them. In such a situation, surgery is necessary to remove them. In the worst case scenario, it can result in death.

Neodymium magnets are the strongest, most remarkable magnets on earth, and the surprising force between them can shock you at first.

On our website, you can find information on how to use neodymium magnets. This will help you avoid injuries and prevent damage to the magnets.

To illustrate why neodymium magnets are so dangerous, read the article - How very dangerous are powerful neodymium magnets?.

Dhit sp. z o.o. logo

e-mail: bok@dhit.pl

tel: +48 888 99 98 98