MP 8x6/3.5x3 / N38 - ring magnet
ring magnet
Catalog no 030206
GTIN/EAN: 5906301812234
- Diameter
- 8 mm [±0,1 mm]
- internal diameter Ø
- 6/3.5 mm [±0,1 mm]
- Height
- 3 mm [±0,1 mm]
- Weight
- 0.91 g
- Magnetization Direction
- ↑ axial
- Coating
- [NiCuNi] Nickel
How we measure these parameters — certificates and measurements
0.570 zł net / pcs
0.701 zł with VAT (23% VAT) / pcs
bulk discounts:
Need more?Frequently asked questions
What is the hole in a ring magnet for?
What is the polarisation?
What sizes are available?
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 details - MP 8x6/3.5x3 / N38 - ring magnet
Specification / characteristics - MP 8x6/3.5x3 / N38 - ring magnet
| properties | values |
|---|---|
| Cat. no. | 030206 |
| GTIN/EAN | 5906301812234 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| Diameter | 8 mm [±0,1 mm] |
| internal diameter Ø | 6/3.5 mm [±0,1 mm] |
| Height | 3 mm [±0,1 mm] |
| Weight | 0.91 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 1.37 kg / 13.48 N |
| Magnetic Induction ~ ? | 371.53 mT / 3715 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 |
Technical simulation of the magnet - technical parameters
These data are the outcome of a engineering simulation. Results are based on models for the material Nd2Fe14B. Actual parameters may differ. Treat these data as a reference point for designers.
Table 1: Static force (force vs distance) - power drop
MP 8x6/3.5x3 / N38
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg/lbs/g/N) | Risk Status |
|---|---|---|---|
| 0 mm |
3327 Gs
332.7 mT
|
1.37 kg / 3.02 LBS
1370.0 g / 13.4 N
|
safe |
| 1 mm |
2612 Gs
261.2 mT
|
0.84 kg / 1.86 LBS
844.4 g / 8.3 N
|
safe |
| 2 mm |
1884 Gs
188.4 mT
|
0.44 kg / 0.97 LBS
439.3 g / 4.3 N
|
safe |
| 3 mm |
1310 Gs
131.0 mT
|
0.21 kg / 0.47 LBS
212.4 g / 2.1 N
|
safe |
| 5 mm |
637 Gs
63.7 mT
|
0.05 kg / 0.11 LBS
50.3 g / 0.5 N
|
safe |
| 10 mm |
151 Gs
15.1 mT
|
0.00 kg / 0.01 LBS
2.8 g / 0.0 N
|
safe |
| 15 mm |
54 Gs
5.4 mT
|
0.00 kg / 0.00 LBS
0.4 g / 0.0 N
|
safe |
| 20 mm |
25 Gs
2.5 mT
|
0.00 kg / 0.00 LBS
0.1 g / 0.0 N
|
safe |
| 30 mm |
8 Gs
0.8 mT
|
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
safe |
| 50 mm |
2 Gs
0.2 mT
|
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
safe |
Table 2: Sliding hold (wall)
MP 8x6/3.5x3 / N38
| Distance (mm) | Friction coefficient | Pull Force (kg/lbs/g/N) |
|---|---|---|
| 0 mm | Stal (~0.2) |
0.27 kg / 0.60 LBS
274.0 g / 2.7 N
|
| 1 mm | Stal (~0.2) |
0.17 kg / 0.37 LBS
168.0 g / 1.6 N
|
| 2 mm | Stal (~0.2) |
0.09 kg / 0.19 LBS
88.0 g / 0.9 N
|
| 3 mm | Stal (~0.2) |
0.04 kg / 0.09 LBS
42.0 g / 0.4 N
|
| 5 mm | Stal (~0.2) |
0.01 kg / 0.02 LBS
10.0 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 (shearing) - behavior on slippery surfaces
MP 8x6/3.5x3 / N38
| Surface type | Friction coefficient / % Mocy | Max load (kg/lbs/g/N) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
0.41 kg / 0.91 LBS
411.0 g / 4.0 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
0.27 kg / 0.60 LBS
274.0 g / 2.7 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
0.14 kg / 0.30 LBS
137.0 g / 1.3 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
0.69 kg / 1.51 LBS
685.0 g / 6.7 N
|
Table 4: Steel thickness (substrate influence) - sheet metal selection
MP 8x6/3.5x3 / N38
| Steel thickness (mm) | % power | Real pull force (kg/lbs/g/N) |
|---|---|---|
| 0.5 mm |
|
0.14 kg / 0.30 LBS
137.0 g / 1.3 N
|
| 1 mm |
|
0.34 kg / 0.76 LBS
342.5 g / 3.4 N
|
| 2 mm |
|
0.69 kg / 1.51 LBS
685.0 g / 6.7 N
|
| 3 mm |
|
1.03 kg / 2.27 LBS
1027.5 g / 10.1 N
|
| 5 mm |
|
1.37 kg / 3.02 LBS
1370.0 g / 13.4 N
|
| 10 mm |
|
1.37 kg / 3.02 LBS
1370.0 g / 13.4 N
|
| 11 mm |
|
1.37 kg / 3.02 LBS
1370.0 g / 13.4 N
|
| 12 mm |
|
1.37 kg / 3.02 LBS
1370.0 g / 13.4 N
|
Table 5: Thermal stability (material behavior) - resistance threshold
MP 8x6/3.5x3 / N38
| Ambient temp. (°C) | Power loss | Remaining pull (kg/lbs/g/N) | Status |
|---|---|---|---|
| 20 °C | 0.0% |
1.37 kg / 3.02 LBS
1370.0 g / 13.4 N
|
OK |
| 40 °C | -2.2% |
1.34 kg / 2.95 LBS
1339.9 g / 13.1 N
|
OK |
| 60 °C | -4.4% |
1.31 kg / 2.89 LBS
1309.7 g / 12.8 N
|
|
| 80 °C | -6.6% |
1.28 kg / 2.82 LBS
1279.6 g / 12.6 N
|
|
| 100 °C | -28.8% |
0.98 kg / 2.15 LBS
975.4 g / 9.6 N
|
Table 6: Two magnets (attraction) - field range
MP 8x6/3.5x3 / N38
| Gap (mm) | Attraction (kg/lbs) (N-S) | Lateral Force (kg/lbs/g/N) | Repulsion (kg/lbs) (N-N) |
|---|---|---|---|
| 0 mm |
2.36 kg / 5.20 LBS
4 867 Gs
|
0.35 kg / 0.78 LBS
354 g / 3.5 N
|
N/A |
| 1 mm |
1.90 kg / 4.20 LBS
5 981 Gs
|
0.29 kg / 0.63 LBS
286 g / 2.8 N
|
1.71 kg / 3.78 LBS
~0 Gs
|
| 2 mm |
1.45 kg / 3.20 LBS
5 223 Gs
|
0.22 kg / 0.48 LBS
218 g / 2.1 N
|
1.31 kg / 2.88 LBS
~0 Gs
|
| 3 mm |
1.06 kg / 2.34 LBS
4 468 Gs
|
0.16 kg / 0.35 LBS
159 g / 1.6 N
|
0.96 kg / 2.11 LBS
~0 Gs
|
| 5 mm |
0.53 kg / 1.16 LBS
3 148 Gs
|
0.08 kg / 0.17 LBS
79 g / 0.8 N
|
0.47 kg / 1.05 LBS
~0 Gs
|
| 10 mm |
0.09 kg / 0.19 LBS
1 274 Gs
|
0.01 kg / 0.03 LBS
13 g / 0.1 N
|
0.08 kg / 0.17 LBS
~0 Gs
|
| 20 mm |
0.00 kg / 0.01 LBS
301 Gs
|
0.00 kg / 0.00 LBS
1 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
| 50 mm |
0.00 kg / 0.00 LBS
27 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
16 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
10 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
7 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
5 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
4 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
Table 7: Protective zones (implants) - warnings
MP 8x6/3.5x3 / N38
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 4.0 cm |
| Hearing aid | 10 Gs (1.0 mT) | 3.0 cm |
| Timepiece | 20 Gs (2.0 mT) | 2.5 cm |
| Mobile device | 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: Dynamics (cracking risk) - warning
MP 8x6/3.5x3 / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
25.61 km/h
(7.11 m/s)
|
0.02 J | |
| 30 mm |
25.64 km/h
(7.12 m/s)
|
0.02 J | |
| 50 mm |
25.64 km/h
(7.12 m/s)
|
0.02 J | |
| 100 mm |
25.64 km/h
(7.12 m/s)
|
0.02 J |
Table 9: Coating parameters (durability)
MP 8x6/3.5x3 / 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)
MP 8x6/3.5x3 / N38
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 1 299 Mx | 13.0 µWb |
| Pc Coefficient | 0.46 | Low (Flat) |
Table 11: Underwater work (magnet fishing)
MP 8x6/3.5x3 / N38
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 1.37 kg | Standard |
| Water (riverbed) |
1.57 kg
(+0.20 kg buoyancy gain)
|
+14.5% |
1. Vertical hold
*Note: On a vertical surface, the magnet retains merely a fraction of its perpendicular strength.
2. Steel saturation
*Thin metal sheet (e.g. computer case) drastically weakens the holding force.
3. Thermal stability
*For N38 grade, the max working temp is 80°C.
4. Demagnetization curve and operating point (B-H)
chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.46
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.
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 |
Check out also proposals
Pros as well as cons of rare earth magnets.
Strengths
- They do not lose strength, even over approximately ten years – the reduction in power is only ~1% (according to tests),
- Magnets perfectly resist against loss of magnetization caused by external fields,
- The use of an refined coating of noble metals (nickel, gold, silver) causes the element to have aesthetics,
- They feature high magnetic induction at the operating surface, making them more effective,
- Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures approaching 230°C and above...
- Thanks to modularity in constructing and the ability to modify to client solutions,
- Versatile presence in modern industrial fields – they find application in HDD drives, drive modules, precision medical tools, and complex engineering applications.
- Compactness – despite small sizes they generate large force, making them ideal for precision applications
Cons
- At strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
- Neodymium magnets lose strength 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
- When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
- We suggest cover - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complicated forms.
- Health risk resulting from small fragments of magnets are risky, if swallowed, which is particularly important in the context of child safety. Furthermore, small elements of these magnets can complicate diagnosis medical after entering the body.
- Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications
Pull force analysis
Optimal lifting capacity of a neodymium magnet – what contributes to it?
- on a block made of structural steel, optimally conducting the magnetic flux
- whose thickness reaches at least 10 mm
- with a plane perfectly flat
- with direct contact (no coatings)
- for force acting at a right angle (pull-off, not shear)
- at temperature approx. 20 degrees Celsius
Practical aspects of lifting capacity – factors
- Gap (betwixt the magnet and the plate), as even a tiny clearance (e.g. 0.5 mm) results in a decrease in lifting capacity by up to 50% (this also applies to varnish, corrosion or dirt).
- Loading method – catalog parameter refers to detachment vertically. When attempting to slide, the magnet exhibits significantly lower power (typically approx. 20-30% of maximum force).
- Base massiveness – insufficiently thick sheet does not accept the full field, causing part of the power to be escaped into the air.
- Material composition – different alloys attracts identically. High carbon content weaken the attraction effect.
- Plate texture – smooth surfaces guarantee perfect abutment, which increases field saturation. Uneven metal weaken the grip.
- Thermal environment – temperature increase causes a temporary drop of force. Check the thermal limit for a given model.
Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under parallel forces the load capacity is reduced by as much as fivefold. Additionally, even a minimal clearance between the magnet and the plate reduces the load capacity.
Safety rules for work with neodymium magnets
Keep away from electronics
A strong magnetic field negatively affects the operation of compasses in smartphones and navigation systems. Maintain magnets near a smartphone to prevent damaging the sensors.
Danger to the youngest
NdFeB magnets are not intended for children. Accidental ingestion of several magnets may result in them pinching intestinal walls, which poses a direct threat to life and requires immediate surgery.
Allergic reactions
Certain individuals suffer from a contact allergy to nickel, which is the standard coating for neodymium magnets. Extended handling can result in a rash. We recommend wear safety gloves.
Do not underestimate power
Use magnets consciously. Their powerful strength can shock even experienced users. Plan your moves and do not underestimate their force.
Shattering risk
Neodymium magnets are sintered ceramics, meaning they are very brittle. Collision of two magnets leads to them cracking into small pieces.
Electronic hazard
Do not bring magnets close to a purse, computer, or screen. The magnetism can destroy these devices and wipe information from cards.
Operating temperature
Keep cool. NdFeB magnets are susceptible to heat. If you require operation above 80°C, ask us about special high-temperature series (H, SH, UH).
Dust explosion hazard
Drilling and cutting of NdFeB material carries a risk of fire hazard. Neodymium dust reacts violently with oxygen and is difficult to extinguish.
Pinching danger
Large magnets can crush fingers instantly. Do not put your hand between two attracting surfaces.
ICD Warning
Patients with a ICD have to maintain an safe separation from magnets. The magnetism can disrupt the functioning of the implant.
