MW 40x8 / N38 - cylindrical magnet
cylindrical magnet
Catalog no 010069
GTIN/EAN: 5906301810681
- Diameter Ø
- 40 mm [±0,1 mm]
- Height
- 8 mm [±0,1 mm]
- Weight
- 75.4 g
- Magnetization Direction
- ↑ axial
- Coating
- [NiCuNi] Nickel
How we measure these parameters — certificates and measurements
25.42 zł net / pcs
31.27 zł with VAT (23% VAT) / pcs
bulk discounts:
Need more?Frequently asked questions
What is the maximum working temperature of a disc magnet?
What is the difference between N38, N42 and N52?
What is the dimensional tolerance?
Engineering report for this magnet
Full PDF analysis: pull and shear force, effect of distance, temperature and plate thickness, safety distances and the demagnetization curve.
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Technical - MW 40x8 / N38 - cylindrical magnet
Specification / characteristics - MW 40x8 / N38 - cylindrical magnet
| properties | values |
|---|---|
| Cat. no. | 010069 |
| GTIN/EAN | 5906301810681 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| Diameter Ø | 40 mm [±0,1 mm] |
| Height | 8 mm [±0,1 mm] |
| Weight | 75.4 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 20.43 kg / 200.39 N |
| Magnetic Induction ~ ? | 230.22 mT / 2302 Gs |
| Coating | [NiCuNi] Nickel |
| Manufacturing Tolerance | ±0.1 mm |
Magnetic properties of material N38
| properties | values | units |
|---|---|---|
| Remanence Br ? | 12.2-12.6 | kGs |
| Remanence Br ? | 1220-1260 | mT |
| Coercivity bHc ? | 10.8-11.5 | kOe |
| Coercivity bHc ? | 860-915 | kA/m |
| Intrinsic coercivity iHc | ≥ 12 | kOe |
| Intrinsic coercivity iHc | ≥ 955 | kA/m |
| Energy product BHmax ? | 36-38 | BH max MGOe |
| Energy product BHmax ? | 287-303 | BH max KJ/m |
| Maximum working 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 | 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 |
Engineering modeling of the magnet - technical parameters
Presented values are the result of a mathematical simulation. Results are based on models for the material Nd2Fe14B. Operational performance may deviate from the simulation results. Treat these data as a preliminary roadmap when designing systems.
Table 1: Static force (force vs distance) - power drop
MW 40x8 / N38
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg/lbs/g/N) | Risk Status |
|---|---|---|---|
| 0 mm |
2302 Gs
230.2 mT
|
20.43 kg / 45.04 LBS
20430.0 g / 200.4 N
|
dangerous! |
| 1 mm |
2235 Gs
223.5 mT
|
19.25 kg / 42.44 LBS
19252.0 g / 188.9 N
|
dangerous! |
| 2 mm |
2156 Gs
215.6 mT
|
17.92 kg / 39.50 LBS
17917.4 g / 175.8 N
|
dangerous! |
| 3 mm |
2068 Gs
206.8 mT
|
16.49 kg / 36.36 LBS
16490.6 g / 161.8 N
|
dangerous! |
| 5 mm |
1875 Gs
187.5 mT
|
13.56 kg / 29.89 LBS
13556.7 g / 133.0 N
|
dangerous! |
| 10 mm |
1375 Gs
137.5 mT
|
7.29 kg / 16.07 LBS
7287.4 g / 71.5 N
|
warning |
| 15 mm |
959 Gs
95.9 mT
|
3.54 kg / 7.81 LBS
3542.3 g / 34.8 N
|
warning |
| 20 mm |
661 Gs
66.1 mT
|
1.68 kg / 3.71 LBS
1684.9 g / 16.5 N
|
safe |
| 30 mm |
328 Gs
32.8 mT
|
0.41 kg / 0.91 LBS
414.2 g / 4.1 N
|
safe |
| 50 mm |
105 Gs
10.5 mT
|
0.04 kg / 0.09 LBS
42.3 g / 0.4 N
|
safe |
Table 2: Vertical capacity (vertical surface)
MW 40x8 / N38
| Distance (mm) | Friction coefficient | Pull Force (kg/lbs/g/N) |
|---|---|---|
| 0 mm | Stal (~0.2) |
4.09 kg / 9.01 LBS
4086.0 g / 40.1 N
|
| 1 mm | Stal (~0.2) |
3.85 kg / 8.49 LBS
3850.0 g / 37.8 N
|
| 2 mm | Stal (~0.2) |
3.58 kg / 7.90 LBS
3584.0 g / 35.2 N
|
| 3 mm | Stal (~0.2) |
3.30 kg / 7.27 LBS
3298.0 g / 32.4 N
|
| 5 mm | Stal (~0.2) |
2.71 kg / 5.98 LBS
2712.0 g / 26.6 N
|
| 10 mm | Stal (~0.2) |
1.46 kg / 3.21 LBS
1458.0 g / 14.3 N
|
| 15 mm | Stal (~0.2) |
0.71 kg / 1.56 LBS
708.0 g / 6.9 N
|
| 20 mm | Stal (~0.2) |
0.34 kg / 0.74 LBS
336.0 g / 3.3 N
|
| 30 mm | Stal (~0.2) |
0.08 kg / 0.18 LBS
82.0 g / 0.8 N
|
| 50 mm | Stal (~0.2) |
0.01 kg / 0.02 LBS
8.0 g / 0.1 N
|
Table 3: Vertical assembly (sliding) - behavior on slippery surfaces
MW 40x8 / N38
| Surface type | Friction coefficient / % Mocy | Max load (kg/lbs/g/N) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
6.13 kg / 13.51 LBS
6129.0 g / 60.1 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
4.09 kg / 9.01 LBS
4086.0 g / 40.1 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
2.04 kg / 4.50 LBS
2043.0 g / 20.0 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
10.22 kg / 22.52 LBS
10215.0 g / 100.2 N
|
Table 4: Steel thickness (substrate influence) - sheet metal selection
MW 40x8 / N38
| Steel thickness (mm) | % power | Real pull force (kg/lbs/g/N) |
|---|---|---|
| 0.5 mm |
|
1.02 kg / 2.25 LBS
1021.5 g / 10.0 N
|
| 1 mm |
|
2.55 kg / 5.63 LBS
2553.8 g / 25.1 N
|
| 2 mm |
|
5.11 kg / 11.26 LBS
5107.5 g / 50.1 N
|
| 3 mm |
|
7.66 kg / 16.89 LBS
7661.3 g / 75.2 N
|
| 5 mm |
|
12.77 kg / 28.15 LBS
12768.8 g / 125.3 N
|
| 10 mm |
|
20.43 kg / 45.04 LBS
20430.0 g / 200.4 N
|
| 11 mm |
|
20.43 kg / 45.04 LBS
20430.0 g / 200.4 N
|
| 12 mm |
|
20.43 kg / 45.04 LBS
20430.0 g / 200.4 N
|
Table 5: Thermal stability (material behavior) - power drop
MW 40x8 / N38
| Ambient temp. (°C) | Power loss | Remaining pull (kg/lbs/g/N) | Status |
|---|---|---|---|
| 20 °C | 0.0% |
20.43 kg / 45.04 LBS
20430.0 g / 200.4 N
|
OK |
| 40 °C | -2.2% |
19.98 kg / 44.05 LBS
19980.5 g / 196.0 N
|
OK |
| 60 °C | -4.4% |
19.53 kg / 43.06 LBS
19531.1 g / 191.6 N
|
|
| 80 °C | -6.6% |
19.08 kg / 42.07 LBS
19081.6 g / 187.2 N
|
|
| 100 °C | -28.8% |
14.55 kg / 32.07 LBS
14546.2 g / 142.7 N
|
Table 6: Two magnets (repulsion) - field collision
MW 40x8 / N38
| Gap (mm) | Attraction (kg/lbs) (N-S) | Shear Strength (kg/lbs/g/N) | Repulsion (kg/lbs) (N-N) |
|---|---|---|---|
| 0 mm |
41.05 kg / 90.51 LBS
3 871 Gs
|
6.16 kg / 13.58 LBS
6158 g / 60.4 N
|
N/A |
| 1 mm |
39.92 kg / 88.02 LBS
4 540 Gs
|
5.99 kg / 13.20 LBS
5989 g / 58.7 N
|
35.93 kg / 79.22 LBS
~0 Gs
|
| 2 mm |
38.69 kg / 85.29 LBS
4 469 Gs
|
5.80 kg / 12.79 LBS
5803 g / 56.9 N
|
34.82 kg / 76.76 LBS
~0 Gs
|
| 3 mm |
37.38 kg / 82.40 LBS
4 393 Gs
|
5.61 kg / 12.36 LBS
5606 g / 55.0 N
|
33.64 kg / 74.16 LBS
~0 Gs
|
| 5 mm |
34.59 kg / 76.25 LBS
4 226 Gs
|
5.19 kg / 11.44 LBS
5188 g / 50.9 N
|
31.13 kg / 68.63 LBS
~0 Gs
|
| 10 mm |
27.24 kg / 60.06 LBS
3 750 Gs
|
4.09 kg / 9.01 LBS
4086 g / 40.1 N
|
24.52 kg / 54.05 LBS
~0 Gs
|
| 20 mm |
14.64 kg / 32.28 LBS
2 750 Gs
|
2.20 kg / 4.84 LBS
2197 g / 21.5 N
|
13.18 kg / 29.06 LBS
~0 Gs
|
| 50 mm |
1.65 kg / 3.63 LBS
922 Gs
|
0.25 kg / 0.54 LBS
247 g / 2.4 N
|
1.48 kg / 3.26 LBS
~0 Gs
|
| 60 mm |
0.83 kg / 1.84 LBS
656 Gs
|
0.12 kg / 0.28 LBS
125 g / 1.2 N
|
0.75 kg / 1.65 LBS
~0 Gs
|
| 70 mm |
0.44 kg / 0.97 LBS
477 Gs
|
0.07 kg / 0.15 LBS
66 g / 0.6 N
|
0.40 kg / 0.87 LBS
~0 Gs
|
| 80 mm |
0.24 kg / 0.54 LBS
355 Gs
|
0.04 kg / 0.08 LBS
37 g / 0.4 N
|
0.22 kg / 0.49 LBS
~0 Gs
|
| 90 mm |
0.14 kg / 0.31 LBS
270 Gs
|
0.02 kg / 0.05 LBS
21 g / 0.2 N
|
0.13 kg / 0.28 LBS
~0 Gs
|
| 100 mm |
0.09 kg / 0.19 LBS
210 Gs
|
0.01 kg / 0.03 LBS
13 g / 0.1 N
|
0.08 kg / 0.17 LBS
~0 Gs
|
Table 7: Protective zones (electronics) - precautionary measures
MW 40x8 / N38
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 15.5 cm |
| Hearing aid | 10 Gs (1.0 mT) | 12.5 cm |
| Timepiece | 20 Gs (2.0 mT) | 9.5 cm |
| Mobile device | 40 Gs (4.0 mT) | 7.5 cm |
| Car key | 50 Gs (5.0 mT) | 7.0 cm |
| Payment card | 400 Gs (40.0 mT) | 3.0 cm |
| HDD hard drive | 600 Gs (60.0 mT) | 2.5 cm |
Table 8: Impact energy (kinetic energy) - warning
MW 40x8 / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
21.48 km/h
(5.97 m/s)
|
1.34 J | |
| 30 mm |
24.93 km/h
(6.93 m/s)
|
1.81 J | |
| 50 mm |
25.14 km/h
(6.98 m/s)
|
1.84 J | |
| 100 mm |
25.18 km/h
(6.99 m/s)
|
1.84 J |
Table 9: Corrosion resistance
MW 40x8 / 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: Construction data (Pc)
MW 40x8 / N38
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 33 553 Mx | 335.5 µWb |
| Pc Coefficient | 0.29 | Low (Flat) |
Table 11: Hydrostatics and buoyancy
MW 40x8 / N38
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 20.43 kg | Standard |
| Water (riverbed) |
23.39 kg
(+2.96 kg buoyancy gain)
|
+14.5% |
1. Wall mount (shear)
*Warning: On a vertical surface, the magnet retains merely a fraction of its nominal pull.
2. Steel thickness impact
*Thin steel (e.g. 0.5mm PC case) severely limits the holding force.
3. Thermal stability
*For N38 material, the safety limit is 80°C.
4. Demagnetization curve and operating point (B-H)
chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.29
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% |
Sustainability
| recyclability (EoL) | 100% |
| recycled raw materials | ~10% (pre-cons) |
| carbon footprint | low / zredukowany |
| waste code (EWC) | 16 02 16 |
Other offers
Pros as well as cons of neodymium magnets.
Benefits
- Their power remains stable, and after approximately ten years it decreases only by ~1% (according to research),
- Neodymium magnets remain highly resistant to demagnetization caused by magnetic disturbances,
- Thanks to the shiny finish, the coating of nickel, gold-plated, or silver-plated gives an professional appearance,
- Magnetic induction on the top side of the magnet remains maximum,
- Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures reaching 230°C and above...
- Possibility of accurate shaping as well as adapting to defined needs,
- Fundamental importance in modern industrial fields – they are used in mass storage devices, electromotive mechanisms, medical equipment, and other advanced devices.
- Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which allows their use in small systems
Limitations
- To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
- NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
- Magnets exposed to a humid environment can rust. Therefore during using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
- We suggest cover - magnetic mount, due to difficulties in producing threads inside the magnet and complex shapes.
- Potential hazard related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small elements of these magnets can disrupt the diagnostic process medical after entering the body.
- 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
Detachment force of the magnet in optimal conditions – what contributes to it?
- using a sheet made of mild steel, functioning as a magnetic yoke
- with a cross-section no less than 10 mm
- with a surface cleaned and smooth
- with direct contact (without paint)
- for force applied at a right angle (pull-off, not shear)
- at temperature approx. 20 degrees Celsius
Magnet lifting force in use – key factors
- Distance (betwixt the magnet and the plate), because even a microscopic clearance (e.g. 0.5 mm) leads to a reduction in force by up to 50% (this also applies to paint, corrosion or dirt).
- Force direction – declared lifting capacity refers to detachment vertically. When slipping, the magnet exhibits significantly lower power (typically approx. 20-30% of nominal force).
- Base massiveness – insufficiently thick plate causes magnetic saturation, causing part of the power to be lost to the other side.
- Steel type – low-carbon steel gives the best results. Higher carbon content decrease magnetic properties and holding force.
- Plate texture – smooth surfaces guarantee perfect abutment, which increases force. Rough surfaces weaken the grip.
- Temperature influence – high temperature reduces pulling force. Exceeding the limit temperature can permanently damage the magnet.
Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under shearing force the holding force is lower. Moreover, even a slight gap between the magnet’s surface and the plate decreases the load capacity.
Warnings
Data carriers
Data protection: Neodymium magnets can ruin payment cards and delicate electronics (heart implants, hearing aids, timepieces).
Conscious usage
Use magnets with awareness. Their powerful strength can surprise even experienced users. Stay alert and respect their power.
Finger safety
Protect your hands. Two large magnets will join immediately with a force of massive weight, destroying everything in their path. Be careful!
Medical interference
Warning for patients: Strong magnetic fields affect electronics. Maintain at least 30 cm distance or request help to work with the magnets.
Warning for allergy sufferers
Certain individuals have a contact allergy to nickel, which is the common plating for NdFeB magnets. Extended handling can result in skin redness. We suggest use protective gloves.
Dust is flammable
Drilling and cutting of NdFeB material poses a fire risk. Neodymium dust reacts violently with oxygen and is hard to extinguish.
GPS Danger
Remember: rare earth magnets generate a field that disrupts precision electronics. Keep a separation from your mobile, device, and navigation systems.
Beware of splinters
Despite metallic appearance, the material is brittle and cannot withstand shocks. Avoid impacts, as the magnet may shatter into sharp, dangerous pieces.
Demagnetization risk
Do not overheat. Neodymium magnets are sensitive to temperature. If you require operation above 80°C, ask us about special high-temperature series (H, SH, UH).
Keep away from children
Neodymium magnets are not intended for children. Accidental ingestion of several magnets may result in them connecting inside the digestive tract, which poses a severe health hazard and necessitates urgent medical intervention.
