MP 62x42x25 / N38 - ring magnet
ring magnet
Catalog no 030205
GTIN/EAN: 5906301812227
Diameter
62 mm [±0,1 mm]
internal diameter Ø
42 mm [±0,1 mm]
Height
25 mm [±0,1 mm]
Weight
306.31 g
Magnetization Direction
↑ axial
Load capacity
58.67 kg / 575.60 N
Magnetic Induction
389.14 mT / 3891 Gs
Coating
[NiCuNi] Nickel
165.00 ZŁ with VAT / pcs + price for transport
134.15 ZŁ net + 23% VAT / pcs
bulk discounts:
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Technical specification - MP 62x42x25 / N38 - ring magnet
Specification / characteristics - MP 62x42x25 / N38 - ring magnet
| properties | values |
|---|---|
| Cat. no. | 030205 |
| GTIN/EAN | 5906301812227 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| Diameter | 62 mm [±0,1 mm] |
| internal diameter Ø | 42 mm [±0,1 mm] |
| Height | 25 mm [±0,1 mm] |
| Weight | 306.31 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 58.67 kg / 575.60 N |
| Magnetic Induction ~ ? | 389.14 mT / 3891 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 analysis of the magnet - data
Presented values are the direct effect of a engineering calculation. Results rely on models for the class Nd2Fe14B. Actual parameters may deviate from the simulation results. Use these data as a reference point for designers.
Table 1: Static force (force vs gap) - interaction chart
MP 62x42x25 / N38
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg/lbs/g/N) | Risk Status |
|---|---|---|---|
| 0 mm |
4472 Gs
447.2 mT
|
58.67 kg / 129.35 LBS
58670.0 g / 575.6 N
|
critical level |
| 1 mm |
4338 Gs
433.8 mT
|
55.21 kg / 121.72 LBS
55213.2 g / 541.6 N
|
critical level |
| 2 mm |
4201 Gs
420.1 mT
|
51.77 kg / 114.13 LBS
51768.5 g / 507.8 N
|
critical level |
| 3 mm |
4061 Gs
406.1 mT
|
48.39 kg / 106.69 LBS
48394.9 g / 474.8 N
|
critical level |
| 5 mm |
3781 Gs
378.1 mT
|
41.94 kg / 92.47 LBS
41942.4 g / 411.5 N
|
critical level |
| 10 mm |
3097 Gs
309.7 mT
|
28.15 kg / 62.06 LBS
28148.0 g / 276.1 N
|
critical level |
| 15 mm |
2485 Gs
248.5 mT
|
18.12 kg / 39.94 LBS
18118.5 g / 177.7 N
|
critical level |
| 20 mm |
1972 Gs
197.2 mT
|
11.41 kg / 25.16 LBS
11412.7 g / 112.0 N
|
critical level |
| 30 mm |
1239 Gs
123.9 mT
|
4.51 kg / 9.93 LBS
4505.2 g / 44.2 N
|
strong |
| 50 mm |
533 Gs
53.3 mT
|
0.83 kg / 1.84 LBS
832.4 g / 8.2 N
|
weak grip |
Table 2: Vertical capacity (wall)
MP 62x42x25 / N38
| Distance (mm) | Friction coefficient | Pull Force (kg/lbs/g/N) |
|---|---|---|
| 0 mm | Stal (~0.2) |
11.73 kg / 25.87 LBS
11734.0 g / 115.1 N
|
| 1 mm | Stal (~0.2) |
11.04 kg / 24.34 LBS
11042.0 g / 108.3 N
|
| 2 mm | Stal (~0.2) |
10.35 kg / 22.83 LBS
10354.0 g / 101.6 N
|
| 3 mm | Stal (~0.2) |
9.68 kg / 21.34 LBS
9678.0 g / 94.9 N
|
| 5 mm | Stal (~0.2) |
8.39 kg / 18.49 LBS
8388.0 g / 82.3 N
|
| 10 mm | Stal (~0.2) |
5.63 kg / 12.41 LBS
5630.0 g / 55.2 N
|
| 15 mm | Stal (~0.2) |
3.62 kg / 7.99 LBS
3624.0 g / 35.6 N
|
| 20 mm | Stal (~0.2) |
2.28 kg / 5.03 LBS
2282.0 g / 22.4 N
|
| 30 mm | Stal (~0.2) |
0.90 kg / 1.99 LBS
902.0 g / 8.8 N
|
| 50 mm | Stal (~0.2) |
0.17 kg / 0.37 LBS
166.0 g / 1.6 N
|
Table 3: Vertical assembly (sliding) - behavior on slippery surfaces
MP 62x42x25 / N38
| Surface type | Friction coefficient / % Mocy | Max load (kg/lbs/g/N) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
17.60 kg / 38.80 LBS
17601.0 g / 172.7 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
11.73 kg / 25.87 LBS
11734.0 g / 115.1 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
5.87 kg / 12.93 LBS
5867.0 g / 57.6 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
29.34 kg / 64.67 LBS
29335.0 g / 287.8 N
|
Table 4: Material efficiency (substrate influence) - power losses
MP 62x42x25 / N38
| Steel thickness (mm) | % power | Real pull force (kg/lbs/g/N) |
|---|---|---|
| 0.5 mm |
|
1.96 kg / 4.31 LBS
1955.7 g / 19.2 N
|
| 1 mm |
|
4.89 kg / 10.78 LBS
4889.2 g / 48.0 N
|
| 2 mm |
|
9.78 kg / 21.56 LBS
9778.3 g / 95.9 N
|
| 3 mm |
|
14.67 kg / 32.34 LBS
14667.5 g / 143.9 N
|
| 5 mm |
|
24.45 kg / 53.89 LBS
24445.8 g / 239.8 N
|
| 10 mm |
|
48.89 kg / 107.79 LBS
48891.7 g / 479.6 N
|
| 11 mm |
|
53.78 kg / 118.57 LBS
53780.8 g / 527.6 N
|
| 12 mm |
|
58.67 kg / 129.35 LBS
58670.0 g / 575.6 N
|
Table 5: Thermal resistance (stability) - thermal limit
MP 62x42x25 / N38
| Ambient temp. (°C) | Power loss | Remaining pull (kg/lbs/g/N) | Status |
|---|---|---|---|
| 20 °C | 0.0% |
58.67 kg / 129.35 LBS
58670.0 g / 575.6 N
|
OK |
| 40 °C | -2.2% |
57.38 kg / 126.50 LBS
57379.3 g / 562.9 N
|
OK |
| 60 °C | -4.4% |
56.09 kg / 123.65 LBS
56088.5 g / 550.2 N
|
OK |
| 80 °C | -6.6% |
54.80 kg / 120.81 LBS
54797.8 g / 537.6 N
|
|
| 100 °C | -28.8% |
41.77 kg / 92.09 LBS
41773.0 g / 409.8 N
|
Table 6: Magnet-Magnet interaction (repulsion) - forces in the system
MP 62x42x25 / N38
| Gap (mm) | Attraction (kg/lbs) (N-S) | Shear Strength (kg/lbs/g/N) | Repulsion (kg/lbs) (N-N) |
|---|---|---|---|
| 0 mm |
264.93 kg / 584.07 LBS
5 588 Gs
|
39.74 kg / 87.61 LBS
39740 g / 389.8 N
|
N/A |
| 1 mm |
257.19 kg / 567.00 LBS
8 812 Gs
|
38.58 kg / 85.05 LBS
38578 g / 378.4 N
|
231.47 kg / 510.30 LBS
~0 Gs
|
| 2 mm |
249.32 kg / 549.66 LBS
8 676 Gs
|
37.40 kg / 82.45 LBS
37398 g / 366.9 N
|
224.39 kg / 494.69 LBS
~0 Gs
|
| 3 mm |
241.51 kg / 532.44 LBS
8 539 Gs
|
36.23 kg / 79.87 LBS
36227 g / 355.4 N
|
217.36 kg / 479.19 LBS
~0 Gs
|
| 5 mm |
226.10 kg / 498.47 LBS
8 262 Gs
|
33.92 kg / 74.77 LBS
33915 g / 332.7 N
|
203.49 kg / 448.62 LBS
~0 Gs
|
| 10 mm |
189.40 kg / 417.55 LBS
7 562 Gs
|
28.41 kg / 62.63 LBS
28409 g / 278.7 N
|
170.46 kg / 375.79 LBS
~0 Gs
|
| 20 mm |
127.11 kg / 280.22 LBS
6 195 Gs
|
19.07 kg / 42.03 LBS
19066 g / 187.0 N
|
114.40 kg / 252.20 LBS
~0 Gs
|
| 50 mm |
32.28 kg / 71.17 LBS
3 122 Gs
|
4.84 kg / 10.68 LBS
4843 g / 47.5 N
|
29.06 kg / 64.06 LBS
~0 Gs
|
| 60 mm |
20.34 kg / 44.85 LBS
2 478 Gs
|
3.05 kg / 6.73 LBS
3052 g / 29.9 N
|
18.31 kg / 40.36 LBS
~0 Gs
|
| 70 mm |
12.99 kg / 28.63 LBS
1 980 Gs
|
1.95 kg / 4.29 LBS
1948 g / 19.1 N
|
11.69 kg / 25.77 LBS
~0 Gs
|
| 80 mm |
8.43 kg / 18.59 LBS
1 595 Gs
|
1.26 kg / 2.79 LBS
1265 g / 12.4 N
|
7.59 kg / 16.73 LBS
~0 Gs
|
| 90 mm |
5.58 kg / 12.29 LBS
1 298 Gs
|
0.84 kg / 1.84 LBS
836 g / 8.2 N
|
5.02 kg / 11.06 LBS
~0 Gs
|
| 100 mm |
3.76 kg / 8.29 LBS
1 065 Gs
|
0.56 kg / 1.24 LBS
564 g / 5.5 N
|
3.38 kg / 7.46 LBS
~0 Gs
|
Table 7: Safety (HSE) (implants) - warnings
MP 62x42x25 / N38
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 32.5 cm |
| Hearing aid | 10 Gs (1.0 mT) | 25.5 cm |
| Timepiece | 20 Gs (2.0 mT) | 20.0 cm |
| Phone / Smartphone | 40 Gs (4.0 mT) | 15.5 cm |
| Car key | 50 Gs (5.0 mT) | 14.0 cm |
| Payment card | 400 Gs (40.0 mT) | 6.0 cm |
| HDD hard drive | 600 Gs (60.0 mT) | 5.0 cm |
Table 8: Impact energy (kinetic energy) - warning
MP 62x42x25 / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
17.65 km/h
(4.90 m/s)
|
3.68 J | |
| 30 mm |
25.31 km/h
(7.03 m/s)
|
7.57 J | |
| 50 mm |
31.49 km/h
(8.75 m/s)
|
11.72 J | |
| 100 mm |
44.16 km/h
(12.27 m/s)
|
23.04 J |
Table 9: Surface protection spec
MP 62x42x25 / 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 (Pc)
MP 62x42x25 / N38
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 100 906 Mx | 1009.1 µWb |
| Pc Coefficient | 0.64 | High (Stable) |
Table 11: Underwater work (magnet fishing)
MP 62x42x25 / N38
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 58.67 kg | Standard |
| Water (riverbed) |
67.18 kg
(+8.51 kg buoyancy gain)
|
+14.5% |
1. Shear force
*Note: On a vertical wall, the magnet retains just a fraction of its perpendicular strength.
2. Steel saturation
*Thin steel (e.g. 0.5mm PC case) severely weakens the holding force.
3. Power loss vs temp
*For standard magnets, the safety limit is 80°C.
4. Demagnetization curve and operating point (B-H)
chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.64
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.
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 |
Other offers
Pros and cons of rare earth magnets.
Strengths
- They retain full power for nearly 10 years – the drop is just ~1% (in theory),
- They maintain their magnetic properties even under strong external field,
- The use of an aesthetic finish of noble metals (nickel, gold, silver) causes the element to have aesthetics,
- The surface of neodymium magnets generates a intense magnetic field – this is one of their assets,
- Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
- Possibility of exact machining as well as adapting to atypical applications,
- Fundamental importance in electronics industry – they find application in HDD drives, electromotive mechanisms, medical equipment, as well as multitasking production systems.
- Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which allows their use in small systems
Weaknesses
- At very strong impacts they can crack, therefore we recommend placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
- We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
- Magnets exposed to a humid environment can rust. Therefore when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
- Due to limitations in realizing nuts and complicated forms in magnets, we propose using cover - magnetic mount.
- Potential hazard to health – tiny shards of magnets pose a threat, in case of ingestion, which becomes key in the context of child safety. Additionally, tiny parts of these devices can disrupt the diagnostic process medical in case of swallowing.
- Due to complex production process, their price is relatively high,
Pull force analysis
Maximum holding power of the magnet – what it depends on?
- using a base made of low-carbon steel, serving as a ideal flux conductor
- whose transverse dimension reaches at least 10 mm
- with a surface perfectly flat
- without the slightest air gap between the magnet and steel
- during detachment in a direction vertical to the mounting surface
- at ambient temperature approx. 20 degrees Celsius
Impact of factors on magnetic holding capacity in practice
- Gap between magnet and steel – every millimeter of distance (caused e.g. by varnish or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
- Force direction – note that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the maximum value.
- Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
- Chemical composition of the base – low-carbon steel attracts best. Higher carbon content lower magnetic properties and lifting capacity.
- Smoothness – full contact is possible only on smooth steel. Rough texture reduce the real contact area, reducing force.
- Thermal factor – hot environment weakens magnetic field. Too high temperature can permanently demagnetize the magnet.
Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under shearing force the holding force is lower. Moreover, even a slight gap between the magnet’s surface and the plate reduces the holding force.
Safe handling of NdFeB magnets
Warning for allergy sufferers
Nickel alert: The nickel-copper-nickel coating consists of nickel. If an allergic reaction occurs, cease working with magnets and wear gloves.
Risk of cracking
Protect your eyes. Magnets can fracture upon violent connection, ejecting shards into the air. Wear goggles.
Keep away from computers
Intense magnetic fields can corrupt files on credit cards, HDDs, and storage devices. Stay away of min. 10 cm.
Crushing risk
Large magnets can break fingers instantly. Under no circumstances place your hand between two attracting surfaces.
Respect the power
Before starting, check safety instructions. Sudden snapping can destroy the magnet or hurt your hand. Be predictive.
Operating temperature
Avoid heat. Neodymium magnets are susceptible to temperature. If you need operation above 80°C, inquire about HT versions (H, SH, UH).
Health Danger
Individuals with a ICD must keep an safe separation from magnets. The magnetic field can disrupt the operation of the implant.
GPS Danger
Navigation devices and smartphones are highly susceptible to magnetism. Direct contact with a powerful NdFeB magnet can permanently damage the internal compass in your phone.
Product not for children
Product intended for adults. Small elements can be swallowed, leading to intestinal necrosis. Store away from kids and pets.
Flammability
Dust generated during cutting of magnets is flammable. Avoid drilling into magnets unless you are an expert.
