MW 8x4 / N38 - cylindrical magnet
cylindrical magnet
Catalog no 010104
GTIN/EAN: 5906301811039
Diameter Ø
8 mm [±0,1 mm]
Height
4 mm [±0,1 mm]
Weight
1.51 g
Magnetization Direction
↑ axial
Load capacity
2.04 kg / 20.00 N
Magnetic Induction
437.78 mT / 4378 Gs
Coating
[NiCuNi] Nickel
0.701 ZŁ with VAT / pcs + price for transport
0.570 ZŁ net + 23% VAT / pcs
bulk discounts:
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Technical details - MW 8x4 / N38 - cylindrical magnet
Specification / characteristics - MW 8x4 / N38 - cylindrical magnet
| properties | values |
|---|---|
| Cat. no. | 010104 |
| GTIN/EAN | 5906301811039 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| Diameter Ø | 8 mm [±0,1 mm] |
| Height | 4 mm [±0,1 mm] |
| Weight | 1.51 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 2.04 kg / 20.00 N |
| Magnetic Induction ~ ? | 437.78 mT / 4378 Gs |
| Coating | [NiCuNi] Nickel |
| Manufacturing Tolerance | ±0.1 mm |
Magnetic properties of material N38
| properties | values | units |
|---|---|---|
| remenance Br [min. - max.] ? | 12.2-12.6 | kGs |
| remenance Br [min. - max.] ? | 1220-1260 | mT |
| coercivity bHc ? | 10.8-11.5 | kOe |
| coercivity bHc ? | 860-915 | kA/m |
| actual internal force iHc | ≥ 12 | kOe |
| actual internal force iHc | ≥ 955 | kA/m |
| energy density [min. - max.] ? | 36-38 | BH max MGOe |
| energy density [min. - max.] ? | 287-303 | BH max KJ/m |
| max. temperature ? | ≤ 80 | °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 | 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 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 |
Physical modeling of the assembly - report
Presented information are the outcome of a physical analysis. Values rely on algorithms for the class Nd2Fe14B. Operational parameters might slightly differ from theoretical values. Please consider these data as a supplementary guide when designing systems.
Table 1: Static force (force vs gap) - power drop
MW 8x4 / N38
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg/lbs/g/N) | Risk Status |
|---|---|---|---|
| 0 mm |
4374 Gs
437.4 mT
|
2.04 kg / 4.50 LBS
2040.0 g / 20.0 N
|
warning |
| 1 mm |
3338 Gs
333.8 mT
|
1.19 kg / 2.62 LBS
1187.8 g / 11.7 N
|
weak grip |
| 2 mm |
2386 Gs
238.6 mT
|
0.61 kg / 1.34 LBS
607.0 g / 6.0 N
|
weak grip |
| 3 mm |
1663 Gs
166.3 mT
|
0.29 kg / 0.65 LBS
294.9 g / 2.9 N
|
weak grip |
| 5 mm |
824 Gs
82.4 mT
|
0.07 kg / 0.16 LBS
72.4 g / 0.7 N
|
weak grip |
| 10 mm |
205 Gs
20.5 mT
|
0.00 kg / 0.01 LBS
4.5 g / 0.0 N
|
weak grip |
| 15 mm |
76 Gs
7.6 mT
|
0.00 kg / 0.00 LBS
0.6 g / 0.0 N
|
weak grip |
| 20 mm |
36 Gs
3.6 mT
|
0.00 kg / 0.00 LBS
0.1 g / 0.0 N
|
weak grip |
| 30 mm |
12 Gs
1.2 mT
|
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
weak grip |
| 50 mm |
3 Gs
0.3 mT
|
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
weak grip |
Table 2: Slippage force (vertical surface)
MW 8x4 / N38
| Distance (mm) | Friction coefficient | Pull Force (kg/lbs/g/N) |
|---|---|---|
| 0 mm | Stal (~0.2) |
0.41 kg / 0.90 LBS
408.0 g / 4.0 N
|
| 1 mm | Stal (~0.2) |
0.24 kg / 0.52 LBS
238.0 g / 2.3 N
|
| 2 mm | Stal (~0.2) |
0.12 kg / 0.27 LBS
122.0 g / 1.2 N
|
| 3 mm | Stal (~0.2) |
0.06 kg / 0.13 LBS
58.0 g / 0.6 N
|
| 5 mm | Stal (~0.2) |
0.01 kg / 0.03 LBS
14.0 g / 0.1 N
|
| 10 mm | Stal (~0.2) |
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
| 15 mm | Stal (~0.2) |
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
| 20 mm | Stal (~0.2) |
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
| 30 mm | Stal (~0.2) |
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
| 50 mm | Stal (~0.2) |
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
Table 3: Vertical assembly (sliding) - behavior on slippery surfaces
MW 8x4 / N38
| Surface type | Friction coefficient / % Mocy | Max load (kg/lbs/g/N) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
0.61 kg / 1.35 LBS
612.0 g / 6.0 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
0.41 kg / 0.90 LBS
408.0 g / 4.0 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
0.20 kg / 0.45 LBS
204.0 g / 2.0 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
1.02 kg / 2.25 LBS
1020.0 g / 10.0 N
|
Table 4: Material efficiency (substrate influence) - power losses
MW 8x4 / N38
| Steel thickness (mm) | % power | Real pull force (kg/lbs/g/N) |
|---|---|---|
| 0.5 mm |
|
0.20 kg / 0.45 LBS
204.0 g / 2.0 N
|
| 1 mm |
|
0.51 kg / 1.12 LBS
510.0 g / 5.0 N
|
| 2 mm |
|
1.02 kg / 2.25 LBS
1020.0 g / 10.0 N
|
| 3 mm |
|
1.53 kg / 3.37 LBS
1530.0 g / 15.0 N
|
| 5 mm |
|
2.04 kg / 4.50 LBS
2040.0 g / 20.0 N
|
| 10 mm |
|
2.04 kg / 4.50 LBS
2040.0 g / 20.0 N
|
| 11 mm |
|
2.04 kg / 4.50 LBS
2040.0 g / 20.0 N
|
| 12 mm |
|
2.04 kg / 4.50 LBS
2040.0 g / 20.0 N
|
Table 5: Working in heat (stability) - power drop
MW 8x4 / N38
| Ambient temp. (°C) | Power loss | Remaining pull (kg/lbs/g/N) | Status |
|---|---|---|---|
| 20 °C | 0.0% |
2.04 kg / 4.50 LBS
2040.0 g / 20.0 N
|
OK |
| 40 °C | -2.2% |
2.00 kg / 4.40 LBS
1995.1 g / 19.6 N
|
OK |
| 60 °C | -4.4% |
1.95 kg / 4.30 LBS
1950.2 g / 19.1 N
|
|
| 80 °C | -6.6% |
1.91 kg / 4.20 LBS
1905.4 g / 18.7 N
|
|
| 100 °C | -28.8% |
1.45 kg / 3.20 LBS
1452.5 g / 14.2 N
|
Table 6: Two magnets (repulsion) - field collision
MW 8x4 / N38
| Gap (mm) | Attraction (kg/lbs) (N-S) | Sliding Force (kg/lbs/g/N) | Repulsion (kg/lbs) (N-N) |
|---|---|---|---|
| 0 mm |
5.93 kg / 13.07 LBS
5 531 Gs
|
0.89 kg / 1.96 LBS
889 g / 8.7 N
|
N/A |
| 1 mm |
4.63 kg / 10.21 LBS
7 730 Gs
|
0.69 kg / 1.53 LBS
694 g / 6.8 N
|
4.17 kg / 9.18 LBS
~0 Gs
|
| 2 mm |
3.45 kg / 7.61 LBS
6 675 Gs
|
0.52 kg / 1.14 LBS
518 g / 5.1 N
|
3.11 kg / 6.85 LBS
~0 Gs
|
| 3 mm |
2.49 kg / 5.50 LBS
5 674 Gs
|
0.37 kg / 0.82 LBS
374 g / 3.7 N
|
2.25 kg / 4.95 LBS
~0 Gs
|
| 5 mm |
1.23 kg / 2.72 LBS
3 989 Gs
|
0.18 kg / 0.41 LBS
185 g / 1.8 N
|
1.11 kg / 2.45 LBS
~0 Gs
|
| 10 mm |
0.21 kg / 0.46 LBS
1 648 Gs
|
0.03 kg / 0.07 LBS
32 g / 0.3 N
|
0.19 kg / 0.42 LBS
~0 Gs
|
| 20 mm |
0.01 kg / 0.03 LBS
410 Gs
|
0.00 kg / 0.00 LBS
2 g / 0.0 N
|
0.01 kg / 0.03 LBS
~0 Gs
|
| 50 mm |
0.00 kg / 0.00 LBS
39 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
| 60 mm |
0.00 kg / 0.00 LBS
24 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
| 70 mm |
0.00 kg / 0.00 LBS
15 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
| 80 mm |
0.00 kg / 0.00 LBS
11 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
| 90 mm |
0.00 kg / 0.00 LBS
8 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
| 100 mm |
0.00 kg / 0.00 LBS
6 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
Table 7: Protective zones (electronics) - warnings
MW 8x4 / N38
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 4.5 cm |
| Hearing aid | 10 Gs (1.0 mT) | 3.5 cm |
| Timepiece | 20 Gs (2.0 mT) | 2.5 cm |
| Phone / Smartphone | 40 Gs (4.0 mT) | 2.0 cm |
| Car key | 50 Gs (5.0 mT) | 2.0 cm |
| Payment card | 400 Gs (40.0 mT) | 1.0 cm |
| HDD hard drive | 600 Gs (60.0 mT) | 1.0 cm |
Table 8: Impact energy (cracking risk) - warning
MW 8x4 / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
37.12 km/h
(10.31 m/s)
|
0.08 J | |
| 30 mm |
64.21 km/h
(17.83 m/s)
|
0.24 J | |
| 50 mm |
82.89 km/h
(23.02 m/s)
|
0.40 J | |
| 100 mm |
117.22 km/h
(32.56 m/s)
|
0.80 J |
Table 9: Surface protection spec
MW 8x4 / N38
| Technical parameter | Value / Description |
|---|---|
| Coating type | [NiCuNi] Nickel |
| Layer structure | Nickel - Copper - Nickel |
| Layer thickness | 10-20 µm |
| Salt spray test (SST) ? | 24 h |
| Recommended environment | Indoors only (dry) |
Table 10: Electrical data (Flux)
MW 8x4 / N38
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 2 233 Mx | 22.3 µWb |
| Pc Coefficient | 0.59 | Low (Flat) |
Table 11: Underwater work (magnet fishing)
MW 8x4 / N38
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 2.04 kg | Standard |
| Water (riverbed) |
2.34 kg
(+0.30 kg buoyancy gain)
|
+14.5% |
1. Wall mount (shear)
*Caution: On a vertical wall, the magnet holds merely approx. 20-30% of its perpendicular strength.
2. Steel thickness impact
*Thin steel (e.g. computer case) significantly limits the holding force.
3. Power loss vs temp
*For standard magnets, the max working temp is 80°C.
4. Demagnetization curve and operating point (B-H)
chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.59
This simulation demonstrates the magnetic stability of the selected magnet under specific geometric conditions. The solid red line represents the demagnetization curve (material potential), while the dashed blue line is the load line based on the magnet's geometry. The Pc (Permeance Coefficient), also known as the load line slope, is a dimensionless value that describes the relationship between the magnet's shape and its magnetic stability. The intersection of these two lines (the black dot) is the operating point — it determines the actual magnetic flux density generated by the magnet in this specific configuration. A higher Pc value means the magnet is more 'slender' (tall relative to its area), resulting in a higher operating point and better resistance to irreversible demagnetization caused by external fields or temperature. A value of 0.42 is relatively low (typical for flat magnets), meaning the operating point is closer to the 'knee' of the curve — caution is advised when operating at temperatures near the maximum limit to avoid strength loss.
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 |
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Strengths and weaknesses of Nd2Fe14B magnets.
Benefits
- They do not lose strength, even during around 10 years – the decrease in strength is only ~1% (theoretically),
- Magnets very well resist against loss of magnetization caused by external fields,
- The use of an refined finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
- They are known for high magnetic induction at the operating surface, which increases their power,
- Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
- Thanks to modularity in forming and the ability to customize to specific needs,
- Versatile presence in high-tech industry – they are commonly used in data components, electromotive mechanisms, medical equipment, and technologically advanced constructions.
- Thanks to their power density, small magnets offer high operating force, in miniature format,
Weaknesses
- Brittleness is one of their disadvantages. Upon intense impact they can break. We recommend keeping them in a strong case, which not only protects them against impacts but also raises their durability
- We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
- When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
- Limited possibility of making threads in the magnet and complex shapes - preferred is a housing - magnet mounting.
- Potential hazard resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child health protection. Furthermore, tiny parts of these products are able to disrupt the diagnostic process medical in case of swallowing.
- Due to neodymium price, their price is relatively high,
Holding force characteristics
Best holding force of the magnet in ideal parameters – what affects it?
- using a plate made of low-carbon steel, functioning as a magnetic yoke
- with a cross-section of at least 10 mm
- with an ideally smooth contact surface
- without the slightest air gap between the magnet and steel
- during detachment in a direction perpendicular to the plane
- in neutral thermal conditions
What influences lifting capacity in practice
- Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
- Force direction – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the nominal value.
- Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of converting into lifting capacity.
- Metal type – not every steel reacts the same. High carbon content worsen the attraction effect.
- Smoothness – full contact is possible only on polished steel. Rough texture reduce the real contact area, reducing force.
- 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 testing was performed on a smooth plate of suitable thickness, under a perpendicular pulling force, in contrast under parallel forces the holding force is lower. Additionally, even a slight gap between the magnet and the plate lowers the load capacity.
Warnings
Medical interference
Warning for patients: Strong magnetic fields disrupt electronics. Keep at least 30 cm distance or ask another person to handle the magnets.
Adults only
Only for adults. Tiny parts can be swallowed, leading to serious injuries. Store out of reach of children and animals.
Impact on smartphones
GPS units and mobile phones are highly susceptible to magnetism. Direct contact with a powerful NdFeB magnet can ruin the sensors in your phone.
Cards and drives
Very strong magnetic fields can erase data on payment cards, HDDs, and storage devices. Maintain a gap of min. 10 cm.
Sensitization to coating
Medical facts indicate that nickel (standard magnet coating) is a common allergen. For allergy sufferers, avoid touching magnets with bare hands and choose versions in plastic housing.
Respect the power
Be careful. Rare earth magnets act from a long distance and connect with massive power, often faster than you can react.
Combustion hazard
Fire hazard: Rare earth powder is explosive. Avoid machining magnets without safety gear as this may cause fire.
Permanent damage
Monitor thermal conditions. Exposing the magnet to high heat will destroy its magnetic structure and strength.
Material brittleness
Watch out for shards. Magnets can explode upon violent connection, ejecting shards into the air. Eye protection is mandatory.
Finger safety
Large magnets can break fingers instantly. Do not place your hand betwixt two strong magnets.
