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SM 25x175 [2xM8] / N42 - magnetic separator

magnetic separator

Catalog no 130290

GTIN/EAN: 5906301812838

Diameter Ø
25 mm [±1 mm]
Height
175 mm [±1 mm]
Weight
660 g
Magnetic Flux
~ 6 500 Gauss [±5%]

How we measure these parameters — certificates and measurements

view technical data »

410.00 zł net / pcs

504.30 zł with VAT (23% VAT) / pcs

price for transport

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Frequently asked questions

Which rod should I choose for fine contamination?
For particles below 0.5 mm — a Ø32 mm rod in grade N52, with surface induction of about 10,000 Gs. A Ø25 rod in grade N42 gives about 6,500 Gs and is chosen for contamination above 1 mm: bolts, washers, pieces of wire.
Which rod pitch should I choose?
The narrow pitch, 40 mm centre to centre, for fine free-flowing fractions — it gives denser coverage of the cross-section. The wide pitch, 50 mm, for granulates and for damp, greasy or sticky materials, where a narrow pitch risks the material bridging above the rods.
Why does efficiency drop after a few weeks of operation?
Almost always because the separator has not been cleaned. The layer of captured particles shields the field, and further particles settle on that layer rather than on the rod surface, where the gradient is far stronger. The magnets themselves do not weaken at that rate.

Guides from the knowledge base

Want to talk magnets?

Call us now +48 888 99 98 98 alternatively let us know using contact form the contact section.
Specifications and structure of a neodymium magnet can be estimated using our power calculator.

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Product card - SM 25x175 [2xM8] / N42 - magnetic separator

Specification / characteristics - SM 25x175 [2xM8] / N42 - magnetic separator

properties
properties values
Cat. no. 130290
GTIN/EAN 5906301812838
Production/Distribution Dhit sp. z o.o.
ul. Zielona 14 05-850 Ożarów Mazowiecki PL
Country of origin Poland / China / Germany
Customs code 85059029
Diameter Ø 25 mm [±1 mm]
Height 175 mm [±1 mm]
Weight 660 g
Material Type Stainless steel AISI 304 / A2
Magnetic Flux ~ 6 500 Gauss [±5%]
Size/Mount Quantity 2xM8
Polarity circumferential - 6 poles
Casing Tube Thickness 1 mm
Manufacturing Tolerance ±1 mm

Magnetic properties of material N42

Specification / characteristics SM 25x175 [2xM8] / N42 - magnetic separator
properties values units
Remanence Br ? 12.9-13.2 kGs
Remanence Br ? 1290-1320 mT
Coercivity bHc ? 10.8-12.0 kOe
Coercivity bHc ? 860-955 kA/m
Intrinsic coercivity iHc ≥ 12 kOe
Intrinsic coercivity iHc ≥ 955 kA/m
Energy product BHmax ? 40-42 BH max MGOe
Energy product BHmax ? 318-334 BH max KJ/m
Maximum working temperature ? ≤ 80 °C

Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C

Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C
properties values units
Vickers hardness ≥550 Hv
Density ≥7.4 g/cm3
Curie Temperature TC 310 °C
Curie Temperature TF 590 °F
Specific resistance 150 μΩ⋅cm
Bending strength 250 MPa
Compressive strength 1000~1100 MPa
Thermal expansion parallel (∥) to orientation (M) (3-4) x 10-6 °C-1
Thermal expansion perpendicular (⊥) to orientation (M) -(1-3) x 10-6 °C-1
Young's modulus 1.7 x 104 kg/mm²

Table 1: Rod construction
SM 25x175 [2xM8] / N42

Parameter Value Description / Unit
Diameter (Ø) 25 mm
Total length 175 mm (L)
Active length 139 mm
Section count 6 modules
Dead zone 36 mm (2x 18mm starter)
Weight (est.) ~653 g
Active area 109 cm² (Area)
Housing material AISI 304 1.4301 (Inox)
Surface finish Ra < 0.8 µm Polished
Temp. class 80°C Standard (N)
Force loss (at max °C) -12.8% Reversible loss (physics)
Force (calculated) 10.6 kg (theor.)
Induction (surface) ~6 500 Gauss (Max)
Max T = 80°C. Construction data for M8/M10 thread series.

Chart 2: Field profile (6 sections)

Simulation: 6 magnetic modules (pitch 23 mm).

Chart 3: Temperature performance

Technical and environmental data

Elemental analysis

iron (Fe) 64% – 68%
neodymium (Nd) 29% – 32%
boron (B) 1.1% – 1.2%
dysprosium (Dy) 0.5% – 2.0%
coating (Ni-Cu-Ni) < 0.05%

Environmental data

recyclability (EoL) 100%
recycled raw materials ~10% (pre-cons)
carbon footprint low / zredukowany
waste code (EWC) 16 02 16
Safety card (GPSR)
responsible entity
Dhit sp. z o.o.
ul. Kościuszki 6A, 05-850 Ożarów Mazowiecki
tel: +48 22 499 98 98 | e-mail: bok@dhit.pl
batch number/type
id: 130290-2026
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A magnetic rod is the basic element of building grate separators and magnetic filters. It is commonly used for cleaning flour, sugar, plastic granules, as well as oils and coolants. High magnetic induction on the surface allows catching the finest iron particles.
The construction relies on a sealed, welded stainless steel housing, polished smooth. The core is a precise magnetic system generating high induction (Gauss). Such construction ensures full resistance to corrosion, water, oils, and acids.
Due to the high power of the magnet, direct removal of filings can be troublesome and time-consuming. We recommend sticking packing tape to the cluster of filings and tearing it off together with the contaminants. In industry, cover tubes (so-called Easy Clean system) are used, from which the magnetic insert slides out.
The Gauss value tells us how effectively and deeply the magnet will catch contaminants. For basic machine protection against pieces of iron, standard power is sufficient. High Power versions (~12000-14000 Gs) are necessary for catching metallic dust, oxides, and stainless steel after processing.
We can produce a rod of non-standard length with any mounting termination. The rod end is strictly adapted to the fastening system in your device. We ensure fast realization of special orders and technical advice.

Advantages and disadvantages of Nd2Fe14B magnets.

Strengths

Besides their immense pulling force, neodymium magnets offer the following advantages:
  • They do not lose power, even after approximately ten years – the drop in power is only ~1% (theoretically),
  • They retain their magnetic properties even under external field action,
  • In other words, due to the aesthetic surface of nickel, the element looks attractive,
  • Magnetic induction on the working layer of the magnet turns out to be exceptional,
  • 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 capacity to customize to specific needs,
  • Fundamental importance in advanced technology sectors – they are used in computer drives, motor assemblies, diagnostic systems, as well as modern systems.
  • Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Weaknesses

Disadvantages of neodymium magnets:
  • To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
  • Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
  • They rust in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
  • Limited possibility of making threads in the magnet and complex shapes - preferred is a housing - magnetic holder.
  • Possible danger to health – tiny shards of magnets can be dangerous, if swallowed, which gains importance in the aspect of protecting the youngest. It is also worth noting that tiny parts of these magnets can disrupt the diagnostic process medical in case of swallowing.
  • High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Holding force characteristics

Maximum holding power of the magnet – what it depends on?

Holding force of 0.00 kg is a theoretical maximum value performed under the following configuration:
  • with the contact of a sheet made of special test steel, guaranteeing maximum field concentration
  • possessing a massiveness of min. 10 mm to ensure full flux closure
  • with an polished touching surface
  • with direct contact (no impurities)
  • under axial force direction (90-degree angle)
  • in temp. approx. 20°C

Determinants of lifting force in real conditions

In practice, the actual lifting capacity is determined by several key aspects, presented from the most important:
  • Space between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by veneer or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
  • Force direction – declared lifting capacity refers to detachment vertically. When slipping, the magnet exhibits much less (often approx. 20-30% of nominal force).
  • Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of generating force.
  • Metal type – different alloys reacts the same. Alloy additives weaken the interaction with the magnet.
  • Surface finish – full contact is obtained only on polished steel. Rough texture reduce the real contact area, weakening the magnet.
  • Heat – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

Lifting capacity was measured by applying a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, however under parallel forces the holding force is lower. Moreover, even a small distance between the magnet and the plate decreases the holding force.

Warnings
Magnetic interference

An intense magnetic field negatively affects the functioning of magnetometers in phones and GPS navigation. Maintain magnets close to a smartphone to avoid damaging the sensors.

Allergy Warning

Medical facts indicate that the nickel plating (standard magnet coating) is a potent allergen. For allergy sufferers, prevent direct skin contact and select coated magnets.

Choking Hazard

These products are not toys. Swallowing multiple magnets may result in them connecting inside the digestive tract, which constitutes a direct threat to life and requires urgent medical intervention.

Shattering risk

NdFeB magnets are ceramic materials, meaning they are prone to chipping. Impact of two magnets leads to them cracking into small pieces.

Handling guide

Before use, check safety instructions. Uncontrolled attraction can destroy the magnet or injure your hand. Think ahead.

Fire risk

Dust created during machining of magnets is self-igniting. Do not drill into magnets without proper cooling and knowledge.

Threat to electronics

Avoid bringing magnets close to a wallet, computer, or screen. The magnetism can irreversibly ruin these devices and erase data from cards.

ICD Warning

For implant holders: Powerful magnets affect electronics. Keep at least 30 cm distance or ask another person to work with the magnets.

Bone fractures

Large magnets can break fingers in a fraction of a second. Do not put your hand betwixt two attracting surfaces.

Thermal limits

Watch the temperature. Exposing the magnet above 80 degrees Celsius will permanently weaken its magnetic structure and pulling force.

Security! Want to know more? Read our article: Are neodymium magnets dangerous?