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SM 25x325 [2xM8] / N42 - magnetic separator

magnetic separator

Catalog no 130349

GTIN/EAN: 5906301812975

Diameter Ø
25 mm [±1 mm]
Height
325 mm [±1 mm]
Weight
1260 g
Magnetic Flux
~ 6 500 Gauss [±5%]

How we measure these parameters — certificates and measurements

see specifications »

890.00 zł net / pcs

1094.70 zł with VAT (23% VAT) / pcs

price for transport

bulk discounts:

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price from 5 pcs
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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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Technical details - SM 25x325 [2xM8] / N42 - magnetic separator

Specification / characteristics - SM 25x325 [2xM8] / N42 - magnetic separator

properties
properties values
Cat. no. 130349
GTIN/EAN 5906301812975
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 325 mm [±1 mm]
Weight 1260 g
Material Type Stainless steel AISI 304 / A2
Magnetic Flux ~ 6 500 Gauss [±5%]
Size/Mount Quantity 2xM8
Polarity circumferential - 12 poles
Casing Tube Thickness 1 mm
Manufacturing Tolerance ±1 mm

Magnetic properties of material N42

Specification / characteristics SM 25x325 [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 25x325 [2xM8] / N42

Parameter Value Description / Unit
Diameter (Ø) 25 mm
Total length 325 mm (L)
Active length 289 mm
Section count 12 modules
Dead zone 36 mm (2x 18mm starter)
Weight (est.) ~1212 g
Active area 227 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 (12 sections)

Simulation: 12 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%

Ecology and recycling (GPSR)

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: 130349-2026
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This product serves to effectively catch ferromagnetic contaminants from bulk and liquid products. Its task is separation (separation) of metal filings from the transported material. High magnetic induction on the surface allows catching the finest iron particles.
The construction relies on a sealed, welded stainless steel housing, polished smooth. Inside there is a stack of strong neodymium magnets arranged in a special configuration (magnetic circuit). Thanks to this, the rod is durable, hygienic, and easy to keep clean.
Metal contaminants are strongly attracted, so removing them with a bare hand or glove can be difficult. You can use compressed air or special non-magnetic strippers (rings). For easier operation, it is worth considering ordering a rod in a version with a cleaning sleeve.
The more Gauss, the smaller and more weakly magnetic particles will be effectively caught. The economical version (8kGs) handles large pieces of metal perfectly. For the food and precision industry, we recommend the highest induction parameters.
We fulfill individual orders for bars perfectly matched to your machine or separator. You can choose a mounting method consistent with your technical design. We ensure fast realization of special orders and technical advice.

Advantages and disadvantages of neodymium magnets.

Strengths

In addition to their long-term stability, neodymium magnets provide the following advantages:
  • They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (according to literature),
  • They feature excellent resistance to weakening of magnetic properties due to opposing magnetic fields,
  • Thanks to the elegant finish, the surface of nickel, gold, or silver-plated gives an aesthetic appearance,
  • They feature high magnetic induction at the operating surface, which improves attraction properties,
  • Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
  • Thanks to freedom in constructing and the capacity to adapt to individual projects,
  • Fundamental importance in innovative solutions – they are used in computer drives, drive modules, medical equipment, and industrial machines.
  • Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which makes them useful in compact constructions

Disadvantages

Disadvantages of neodymium magnets:
  • They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
  • We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
  • When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
  • Due to limitations in realizing threads and complicated shapes in magnets, we propose using casing - magnetic holder.
  • Possible danger to health – tiny shards of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child health protection. It is also worth noting that small elements of these products are able to disrupt the diagnostic process medical when they are in the body.
  • Due to complex production process, their price is higher than average,

Lifting parameters

Maximum magnetic pulling force – what it depends on?

The lifting capacity listed is a theoretical maximum value executed under specific, ideal conditions:
  • with the use of a yoke made of special test steel, guaranteeing maximum field concentration
  • with a thickness of at least 10 mm
  • with an ground contact surface
  • under conditions of gap-free contact (surface-to-surface)
  • during detachment in a direction perpendicular to the mounting surface
  • at room temperature

Lifting capacity in practice – influencing factors

In real-world applications, the real power results from a number of factors, listed from crucial:
  • Clearance – the presence of foreign body (paint, tape, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
  • Load vector – highest force is available only during pulling at a 90° angle. The shear force of the magnet along the plate is usually several times smaller (approx. 1/5 of the lifting capacity).
  • Element thickness – for full efficiency, the steel must be adequately massive. Thin sheet limits the lifting capacity (the magnet "punches through" it).
  • Metal type – different alloys reacts the same. High carbon content worsen the interaction with the magnet.
  • Surface structure – the smoother and more polished the plate, the better the adhesion and stronger the hold. Roughness creates an air distance.
  • Operating temperature – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and in frost gain strength (up to a certain limit).

Lifting capacity testing was carried out on a smooth plate of optimal thickness, under perpendicular forces, whereas under attempts to slide the magnet the lifting capacity is smaller. In addition, even a slight gap between the magnet’s surface and the plate decreases the load capacity.

Safe handling of neodymium magnets
Maximum temperature

Do not overheat. NdFeB magnets are sensitive to heat. If you need resistance above 80°C, ask us about special high-temperature series (H, SH, UH).

Fragile material

NdFeB magnets are sintered ceramics, which means they are very brittle. Impact of two magnets will cause them breaking into shards.

Safe distance

Very strong magnetic fields can corrupt files on credit cards, hard drives, and other magnetic media. Keep a distance of at least 10 cm.

ICD Warning

Health Alert: Neodymium magnets can turn off pacemakers and defibrillators. Stay away if you have electronic implants.

Magnetic interference

A strong magnetic field negatively affects the functioning of compasses in phones and navigation systems. Do not bring magnets near a device to prevent breaking the sensors.

Sensitization to coating

Allergy Notice: The Ni-Cu-Ni coating consists of nickel. If an allergic reaction appears, immediately stop handling magnets and wear gloves.

Swallowing risk

NdFeB magnets are not toys. Accidental ingestion of several magnets may result in them connecting inside the digestive tract, which constitutes a direct threat to life and necessitates urgent medical intervention.

Conscious usage

Be careful. Rare earth magnets attract from a long distance and snap with huge force, often faster than you can react.

Do not drill into magnets

Powder generated during machining of magnets is combustible. Avoid drilling into magnets without proper cooling and knowledge.

Crushing force

Protect your hands. Two large magnets will join instantly with a force of several hundred kilograms, crushing anything in their path. Be careful!

Safety First! Need more info? Check our post: Why are neodymium magnets dangerous?