MW 25x5 / N38AH - cylindrical magnet
cylindrical magnet
Catalog no 010501
GTIN/EAN: 5906301814993
- Diameter Ø
- 25 mm [±0,1 mm]
- Height
- 5 mm [±0,1 mm]
- Weight
- 18.41 g
- Magnetization Direction
- ↑ axial
- Coating
- [NiCuNi] Nickel
13.56 zł net / pcs
16.68 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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Detailed specification - MW 25x5 / N38AH - cylindrical magnet
Specification / characteristics - MW 25x5 / N38AH - cylindrical magnet
| properties | values |
|---|---|
| Cat. no. | 010501 |
| GTIN/EAN | 5906301814993 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| Diameter Ø | 25 mm [±0,1 mm] |
| Height | 5 mm [±0,1 mm] |
| Weight | 18.41 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 7.29 kg / 71.47 N |
| Magnetic Induction ~ ? | 219.99 mT / 2200 Gs |
| Coating | [NiCuNi] Nickel |
| Manufacturing Tolerance | ±0.1 mm |
Magnetic properties of material N38AH
| properties | values | units |
|---|---|---|
| remenance Br [min. - max.] ? | 12.2-12.5 | kGs |
| remenance Br [min. - max.] ? | 1120-1250 | mT |
| coercivity bHc ? | ≥ 11.3 | kOe |
| coercivity bHc ? | ≥ 899 | kA/m |
| actual internal force iHc | ≥ 33 | kOe |
| actual internal force iHc | ≥ 2624 | kA/m |
| energy density [min. - max.] ? | 36-39 | BH max MGOe |
| energy density [min. - max.] ? | 287-310 | BH max KJ/m |
| max. temperature ? | ≤ 230 | °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 simulation of the product - technical parameters
Presented values constitute the outcome of a mathematical calculation. Results were calculated on algorithms for the class Nd2Fe14B. Operational parameters might slightly differ from theoretical values. Please consider these calculations as a preliminary roadmap when designing systems.
Table 1: Static pull force (force vs distance) - interaction chart
MW 25x5 / N38AH
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg/lbs/g/N) | Risk Status |
|---|---|---|---|
| 0 mm |
2292 Gs
229.2 mT
|
7.29 kg / 16.07 LBS
7290.0 g / 71.5 N
|
medium risk |
| 1 mm |
2180 Gs
218.0 mT
|
6.59 kg / 14.53 LBS
6591.0 g / 64.7 N
|
medium risk |
| 2 mm |
2042 Gs
204.2 mT
|
5.78 kg / 12.75 LBS
5782.0 g / 56.7 N
|
medium risk |
| 3 mm |
1888 Gs
188.8 mT
|
4.94 kg / 10.90 LBS
4942.8 g / 48.5 N
|
medium risk |
| 5 mm |
1564 Gs
156.4 mT
|
3.39 kg / 7.48 LBS
3394.1 g / 33.3 N
|
medium risk |
| 10 mm |
886 Gs
88.6 mT
|
1.09 kg / 2.40 LBS
1089.7 g / 10.7 N
|
safe |
| 15 mm |
493 Gs
49.3 mT
|
0.34 kg / 0.74 LBS
336.7 g / 3.3 N
|
safe |
| 20 mm |
287 Gs
28.7 mT
|
0.11 kg / 0.25 LBS
114.0 g / 1.1 N
|
safe |
| 30 mm |
115 Gs
11.5 mT
|
0.02 kg / 0.04 LBS
18.4 g / 0.2 N
|
safe |
| 50 mm |
31 Gs
3.1 mT
|
0.00 kg / 0.00 LBS
1.3 g / 0.0 N
|
safe |
Table 2: Slippage capacity (vertical surface)
MW 25x5 / N38AH
| Distance (mm) | Friction coefficient | Pull Force (kg/lbs/g/N) |
|---|---|---|
| 0 mm | Stal (~0.2) |
1.46 kg / 3.21 LBS
1458.0 g / 14.3 N
|
| 1 mm | Stal (~0.2) |
1.32 kg / 2.91 LBS
1318.0 g / 12.9 N
|
| 2 mm | Stal (~0.2) |
1.16 kg / 2.55 LBS
1156.0 g / 11.3 N
|
| 3 mm | Stal (~0.2) |
0.99 kg / 2.18 LBS
988.0 g / 9.7 N
|
| 5 mm | Stal (~0.2) |
0.68 kg / 1.49 LBS
678.0 g / 6.7 N
|
| 10 mm | Stal (~0.2) |
0.22 kg / 0.48 LBS
218.0 g / 2.1 N
|
| 15 mm | Stal (~0.2) |
0.07 kg / 0.15 LBS
68.0 g / 0.7 N
|
| 20 mm | Stal (~0.2) |
0.02 kg / 0.05 LBS
22.0 g / 0.2 N
|
| 30 mm | Stal (~0.2) |
0.00 kg / 0.01 LBS
4.0 g / 0.0 N
|
| 50 mm | Stal (~0.2) |
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
Table 3: Wall mounting (sliding) - behavior on slippery surfaces
MW 25x5 / N38AH
| Surface type | Friction coefficient / % Mocy | Max load (kg/lbs/g/N) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
2.19 kg / 4.82 LBS
2187.0 g / 21.5 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
1.46 kg / 3.21 LBS
1458.0 g / 14.3 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
0.73 kg / 1.61 LBS
729.0 g / 7.2 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
3.65 kg / 8.04 LBS
3645.0 g / 35.8 N
|
Table 4: Steel thickness (saturation) - power losses
MW 25x5 / N38AH
| Steel thickness (mm) | % power | Real pull force (kg/lbs/g/N) |
|---|---|---|
| 0.5 mm |
|
0.73 kg / 1.61 LBS
729.0 g / 7.2 N
|
| 1 mm |
|
1.82 kg / 4.02 LBS
1822.5 g / 17.9 N
|
| 2 mm |
|
3.65 kg / 8.04 LBS
3645.0 g / 35.8 N
|
| 3 mm |
|
5.47 kg / 12.05 LBS
5467.5 g / 53.6 N
|
| 5 mm |
|
7.29 kg / 16.07 LBS
7290.0 g / 71.5 N
|
| 10 mm |
|
7.29 kg / 16.07 LBS
7290.0 g / 71.5 N
|
| 11 mm |
|
7.29 kg / 16.07 LBS
7290.0 g / 71.5 N
|
| 12 mm |
|
7.29 kg / 16.07 LBS
7290.0 g / 71.5 N
|
Table 5: Thermal stability (stability) - power drop
MW 25x5 / N38AH
| Ambient temp. (°C) | Power loss | Remaining pull (kg/lbs/g/N) | Status |
|---|---|---|---|
| 20 °C | 0.0% |
7.29 kg / 16.07 LBS
7290.0 g / 71.5 N
|
OK |
| 80 °C | -6.6% |
6.81 kg / 15.01 LBS
6808.9 g / 66.8 N
|
|
| 150 °C | -14.3% |
6.25 kg / 13.77 LBS
6247.5 g / 61.3 N
|
|
| 200 °C | -19.8% |
5.85 kg / 12.89 LBS
5846.6 g / 57.4 N
|
|
| 230 °C | -23.1% |
5.61 kg / 12.36 LBS
5606.0 g / 55.0 N
|
|
| 250 °C | -45.3% |
3.99 kg / 8.79 LBS
3987.6 g / 39.1 N
|
Table 6: Magnet-Magnet interaction (repulsion) - field range
MW 25x5 / N38AH
| Gap (mm) | Attraction (kg/lbs) (N-S) | Sliding Force (kg/lbs/g/N) | Repulsion (kg/lbs) (N-N) |
|---|---|---|---|
| 0 mm |
15.90 kg / 35.06 LBS
3 855 Gs
|
2.39 kg / 5.26 LBS
2385 g / 23.4 N
|
N/A |
| 1 mm |
15.19 kg / 33.48 LBS
4 480 Gs
|
2.28 kg / 5.02 LBS
2278 g / 22.3 N
|
13.67 kg / 30.13 LBS
~0 Gs
|
| 2 mm |
14.38 kg / 31.70 LBS
4 359 Gs
|
2.16 kg / 4.75 LBS
2157 g / 21.2 N
|
12.94 kg / 28.53 LBS
~0 Gs
|
| 3 mm |
13.51 kg / 29.79 LBS
4 226 Gs
|
2.03 kg / 4.47 LBS
2027 g / 19.9 N
|
12.16 kg / 26.81 LBS
~0 Gs
|
| 5 mm |
11.70 kg / 25.79 LBS
3 932 Gs
|
1.75 kg / 3.87 LBS
1755 g / 17.2 N
|
10.53 kg / 23.21 LBS
~0 Gs
|
| 10 mm |
7.40 kg / 16.32 LBS
3 128 Gs
|
1.11 kg / 2.45 LBS
1111 g / 10.9 N
|
6.66 kg / 14.69 LBS
~0 Gs
|
| 20 mm |
2.38 kg / 5.24 LBS
1 773 Gs
|
0.36 kg / 0.79 LBS
357 g / 3.5 N
|
2.14 kg / 4.72 LBS
~0 Gs
|
| 50 mm |
0.09 kg / 0.21 LBS
354 Gs
|
0.01 kg / 0.03 LBS
14 g / 0.1 N
|
0.09 kg / 0.19 LBS
~0 Gs
|
| 60 mm |
0.04 kg / 0.09 LBS
231 Gs
|
0.01 kg / 0.01 LBS
6 g / 0.1 N
|
0.04 kg / 0.08 LBS
~0 Gs
|
| 70 mm |
0.02 kg / 0.04 LBS
157 Gs
|
0.00 kg / 0.01 LBS
3 g / 0.0 N
|
0.02 kg / 0.04 LBS
~0 Gs
|
| 80 mm |
0.01 kg / 0.02 LBS
112 Gs
|
0.00 kg / 0.00 LBS
1 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
| 90 mm |
0.01 kg / 0.01 LBS
82 Gs
|
0.00 kg / 0.00 LBS
1 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
| 100 mm |
0.00 kg / 0.01 LBS
62 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
Table 7: Hazards (electronics) - precautionary measures
MW 25x5 / N38AH
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 10.0 cm |
| Hearing aid | 10 Gs (1.0 mT) | 7.5 cm |
| Timepiece | 20 Gs (2.0 mT) | 6.0 cm |
| Phone / Smartphone | 40 Gs (4.0 mT) | 5.0 cm |
| Remote | 50 Gs (5.0 mT) | 4.5 cm |
| Payment card | 400 Gs (40.0 mT) | 2.0 cm |
| HDD hard drive | 600 Gs (60.0 mT) | 1.5 cm |
Table 8: Collisions (cracking risk) - collision effects
MW 25x5 / N38AH
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
22.63 km/h
(6.29 m/s)
|
0.36 J | |
| 30 mm |
24.03 km/h
(6.67 m/s)
|
0.41 J | |
| 50 mm |
24.06 km/h
(6.68 m/s)
|
0.41 J | |
| 100 mm |
24.07 km/h
(6.69 m/s)
|
0.41 J |
Table 9: Surface protection spec
MW 25x5 / N38AH
| 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 25x5 / N38AH
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 13 054 Mx | 130.5 µWb |
| Pc Coefficient | 0.29 | Low (Flat) |
Table 11: Submerged application
MW 25x5 / N38AH
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 7.29 kg | Standard |
| Water (riverbed) |
8.35 kg
(+1.06 kg buoyancy gain)
|
+14.5% |
1. Sliding resistance
*Note: On a vertical surface, the magnet holds just a fraction of its max power.
2. Efficiency vs thickness
*Thin steel (e.g. 0.5mm PC case) significantly reduces the holding force.
3. Power loss vs temp
*For N38 grade, the critical limit is 80°C.
4. Demagnetization curve and operating point (B-H)
chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.29
The chart above illustrates the magnetic characteristics of the material within the second quadrant of the hysteresis loop. 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.
Material specification
| 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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Pros as well as cons of neodymium magnets.
Advantages
- Their power is durable, and after approximately ten years it drops only by ~1% (theoretically),
- They retain their magnetic properties even under close interference source,
- Thanks to the metallic finish, the plating of Ni-Cu-Ni, gold, or silver-plated gives an aesthetic appearance,
- The surface of neodymium magnets generates a strong magnetic field – this is one of their assets,
- Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
- In view of the potential of free shaping and adaptation to unique projects, NdFeB magnets can be modeled in a broad palette of forms and dimensions, which increases their versatility,
- Versatile presence in future technologies – they find application in data components, motor assemblies, medical devices, also modern systems.
- Thanks to their power density, small magnets offer high operating force, occupying minimum space,
Limitations
- Susceptibility to cracking is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a strong case, which not only protects them against impacts but also increases 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.
- They rust in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
- We suggest cover - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complicated forms.
- Possible danger to health – tiny shards of magnets can be dangerous, in case of ingestion, which becomes key in the context of child safety. Furthermore, tiny parts of these devices can complicate diagnosis medical when they are in the body.
- Due to expensive raw materials, their price is higher than average,
Holding force characteristics
Maximum lifting capacity of the magnet – what affects it?
- with the use of a sheet made of special test steel, guaranteeing full magnetic saturation
- whose thickness reaches at least 10 mm
- with an ideally smooth contact surface
- with total lack of distance (no impurities)
- for force applied at a right angle (in the magnet axis)
- in neutral thermal conditions
Key elements affecting lifting force
- Gap (between the magnet and the metal), because even a microscopic distance (e.g. 0.5 mm) results in a drastic drop in force by up to 50% (this also applies to varnish, corrosion or debris).
- Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet exhibits much less (often approx. 20-30% of maximum force).
- Base massiveness – too thin steel causes magnetic saturation, causing part of the power to be wasted into the air.
- Material type – ideal substrate is pure iron steel. Stainless steels may attract less.
- Smoothness – full contact is possible only on polished steel. Rough texture reduce the real contact area, weakening the magnet.
- Temperature influence – hot environment weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.
Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under shearing force the lifting capacity is smaller. Additionally, even a slight gap between the magnet’s surface and the plate reduces the holding force.
Precautions when working with neodymium magnets
Flammability
Fire hazard: Rare earth powder is explosive. Do not process magnets without safety gear as this risks ignition.
Serious injuries
Protect your hands. Two powerful magnets will snap together immediately with a force of several hundred kilograms, crushing anything in their path. Be careful!
Life threat
Individuals with a heart stimulator must maintain an safe separation from magnets. The magnetism can stop the operation of the implant.
GPS Danger
GPS units and smartphones are highly sensitive to magnetic fields. Direct contact with a powerful NdFeB magnet can decalibrate the internal compass in your phone.
Handling rules
Be careful. Rare earth magnets act from a long distance and connect with massive power, often quicker than you can move away.
Danger to the youngest
Absolutely keep magnets out of reach of children. Choking hazard is significant, and the consequences of magnets connecting inside the body are fatal.
Magnetic media
Equipment safety: Neodymium magnets can damage payment cards and sensitive devices (pacemakers, medical aids, timepieces).
Operating temperature
Do not overheat. NdFeB magnets are susceptible to temperature. If you need operation above 80°C, ask us about HT versions (H, SH, UH).
Protective goggles
Neodymium magnets are ceramic materials, which means they are prone to chipping. Impact of two magnets will cause them shattering into shards.
Skin irritation risks
Medical facts indicate that nickel (standard magnet coating) is a common allergen. If you have an allergy, avoid touching magnets with bare hands and choose coated magnets.
