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
Load capacity
1.37 kg / 13.48 N
Magnetic Induction
371.53 mT / 3715 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 - 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 |
|---|---|---|
| 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 |
Technical simulation of the magnet - technical parameters
The following values constitute the direct effect of a mathematical simulation. Values were calculated on models for the class Nd2Fe14B. Operational performance may differ from theoretical values. Please consider these calculations as a reference point during assembly planning.
Table 1: Static pull force (force vs gap) - interaction chart
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 force (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) - vertical pull
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: Material efficiency (saturation) - 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 resistance (stability) - 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: Magnet-Magnet interaction (repulsion) - forces in the system
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: Hazards (electronics) - 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 |
| Phone / Smartphone | 40 Gs (4.0 mT) | 2.0 cm |
| Remote | 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 (kinetic energy) - warning
MP 8x6/3.5x3 / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
39.18 km/h
(10.88 m/s)
|
0.05 J | |
| 30 mm |
67.78 km/h
(18.83 m/s)
|
0.16 J | |
| 50 mm |
87.50 km/h
(24.31 m/s)
|
0.27 J | |
| 100 mm |
123.74 km/h
(34.37 m/s)
|
0.54 J |
Table 9: Corrosion resistance
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: Construction 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: Submerged application
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. Shear force
*Caution: On a vertical wall, the magnet retains merely approx. 20-30% of its nominal pull.
2. Efficiency vs thickness
*Thin metal sheet (e.g. 0.5mm PC case) drastically reduces the holding force.
3. Temperature resistance
*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
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% |
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 Nd2Fe14B magnets.
Benefits
- They retain full power for around ten years – the loss is just ~1% (in theory),
- They possess excellent resistance to magnetism drop as a result of external magnetic sources,
- In other words, due to the shiny surface of nickel, the element gains visual value,
- They show high magnetic induction at the operating surface, making them more effective,
- Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
- Thanks to flexibility in constructing and the capacity to customize to specific needs,
- Significant place in modern technologies – they are utilized in mass storage devices, electric drive systems, advanced medical instruments, and technologically advanced constructions.
- Thanks to their power density, small magnets offer high operating force, occupying minimum space,
Weaknesses
- They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also improves its resistance to damage
- 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.
- Magnets exposed to a humid environment can corrode. Therefore during using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
- We recommend casing - magnetic mechanism, due to difficulties in creating threads inside the magnet and complex shapes.
- Possible danger related to microscopic parts of magnets pose a threat, in case of ingestion, which gains importance in the context of child safety. It is also worth noting that small elements of these products are able to be problematic in diagnostics medical in case of swallowing.
- High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which hinders application in large quantities
Holding force characteristics
Maximum lifting force for a neodymium magnet – what it depends on?
- with the contact of a sheet made of special test steel, guaranteeing maximum field concentration
- whose transverse dimension equals approx. 10 mm
- with a plane free of scratches
- under conditions of no distance (metal-to-metal)
- during detachment in a direction vertical to the plane
- at ambient temperature approx. 20 degrees Celsius
Magnet lifting force in use – key factors
- Gap between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
- Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet exhibits much less (often approx. 20-30% of nominal force).
- Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of converting into lifting capacity.
- Steel grade – ideal substrate is pure iron steel. Stainless steels may attract less.
- Surface structure – the more even the surface, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
- Temperature – temperature increase results in weakening of force. Check the maximum operating temperature for a given model.
Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under shearing force the load capacity is reduced by as much as 5 times. Additionally, even a small distance between the magnet’s surface and the plate decreases the lifting capacity.
Safe handling of neodymium magnets
Protective goggles
Despite the nickel coating, the material is brittle and not impact-resistant. Do not hit, as the magnet may shatter into hazardous fragments.
Permanent damage
Monitor thermal conditions. Exposing the magnet to high heat will ruin its properties and strength.
Do not give to children
Absolutely keep magnets away from children. Ingestion danger is high, and the effects of magnets connecting inside the body are life-threatening.
Allergic reactions
Medical facts indicate that nickel (the usual finish) is a strong allergen. If you have an allergy, avoid touching magnets with bare hands or select versions in plastic housing.
Fire risk
Powder created during machining of magnets is flammable. Avoid drilling into magnets unless you are an expert.
Pinching danger
Pinching hazard: The attraction force is so immense that it can cause blood blisters, crushing, and even bone fractures. Protective gloves are recommended.
Caution required
Be careful. Rare earth magnets act from a distance and connect with massive power, often quicker than you can move away.
Cards and drives
Avoid bringing magnets near a purse, computer, or TV. The magnetism can permanently damage these devices and wipe information from cards.
Health Danger
For implant holders: Strong magnetic fields disrupt medical devices. Keep at least 30 cm distance or ask another person to handle the magnets.
Impact on smartphones
Be aware: rare earth magnets produce a field that disrupts sensitive sensors. Maintain a safe distance from your phone, tablet, and navigation systems.
