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MP 30x6x10 / N38 - ring magnet

ring magnet

Catalog no 030197

GTIN/EAN: 5906301812142

5.00

Diameter

30 mm [±0,1 mm]

internal diameter Ø

6 mm [±0,1 mm]

Height

10 mm [±0,1 mm]

Weight

50.89 g

Magnetization Direction

↑ axial

Load capacity

20.71 kg / 203.16 N

Magnetic Induction

343.81 mT / 3438 Gs

Coating

[NiCuNi] Nickel

16.00 with VAT / pcs + price for transport

13.01 ZŁ net + 23% VAT / pcs

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Physical properties - MP 30x6x10 / N38 - ring magnet

Specification / characteristics - MP 30x6x10 / N38 - ring magnet

properties
properties values
Cat. no. 030197
GTIN/EAN 5906301812142
Production/Distribution Dhit sp. z o.o.
ul. Zielona 14 05-850 Ożarów Mazowiecki PL
Country of origin Poland / China / Germany
Customs code 85059029
Diameter 30 mm [±0,1 mm]
internal diameter Ø 6 mm [±0,1 mm]
Height 10 mm [±0,1 mm]
Weight 50.89 g
Magnetization Direction ↑ axial
Load capacity ~ ? 20.71 kg / 203.16 N
Magnetic Induction ~ ? 343.81 mT / 3438 Gs
Coating [NiCuNi] Nickel
Manufacturing Tolerance ±0.1 mm

Magnetic properties of material N38

Specification / characteristics MP 30x6x10 / N38 - ring magnet
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

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

Engineering analysis of the assembly - technical parameters

Presented information represent the result of a mathematical analysis. Results rely on algorithms for the material Nd2Fe14B. Real-world parameters might slightly deviate from the simulation results. Treat these data as a reference point when designing systems.

Table 1: Static pull force (force vs gap) - interaction chart
MP 30x6x10 / N38

Distance (mm) Induction (Gauss) / mT Pull Force (kg/lbs/g/N) Risk Status
0 mm 5619 Gs
561.9 mT
20.71 kg / 45.66 LBS
20710.0 g / 203.2 N
crushing
1 mm 5241 Gs
524.1 mT
18.01 kg / 39.71 LBS
18011.7 g / 176.7 N
crushing
2 mm 4861 Gs
486.1 mT
15.50 kg / 34.17 LBS
15498.1 g / 152.0 N
crushing
3 mm 4490 Gs
449.0 mT
13.22 kg / 29.15 LBS
13223.5 g / 129.7 N
crushing
5 mm 3792 Gs
379.2 mT
9.43 kg / 20.79 LBS
9429.0 g / 92.5 N
warning
10 mm 2404 Gs
240.4 mT
3.79 kg / 8.36 LBS
3791.3 g / 37.2 N
warning
15 mm 1526 Gs
152.6 mT
1.53 kg / 3.37 LBS
1527.0 g / 15.0 N
safe
20 mm 1000 Gs
100.0 mT
0.66 kg / 1.45 LBS
655.5 g / 6.4 N
safe
30 mm 482 Gs
48.2 mT
0.15 kg / 0.34 LBS
152.6 g / 1.5 N
safe
50 mm 161 Gs
16.1 mT
0.02 kg / 0.04 LBS
17.0 g / 0.2 N
safe

Table 2: Vertical hold (vertical surface)
MP 30x6x10 / N38

Distance (mm) Friction coefficient Pull Force (kg/lbs/g/N)
0 mm Stal (~0.2) 4.14 kg / 9.13 LBS
4142.0 g / 40.6 N
1 mm Stal (~0.2) 3.60 kg / 7.94 LBS
3602.0 g / 35.3 N
2 mm Stal (~0.2) 3.10 kg / 6.83 LBS
3100.0 g / 30.4 N
3 mm Stal (~0.2) 2.64 kg / 5.83 LBS
2644.0 g / 25.9 N
5 mm Stal (~0.2) 1.89 kg / 4.16 LBS
1886.0 g / 18.5 N
10 mm Stal (~0.2) 0.76 kg / 1.67 LBS
758.0 g / 7.4 N
15 mm Stal (~0.2) 0.31 kg / 0.67 LBS
306.0 g / 3.0 N
20 mm Stal (~0.2) 0.13 kg / 0.29 LBS
132.0 g / 1.3 N
30 mm Stal (~0.2) 0.03 kg / 0.07 LBS
30.0 g / 0.3 N
50 mm Stal (~0.2) 0.00 kg / 0.01 LBS
4.0 g / 0.0 N

Table 3: Vertical assembly (shearing) - behavior on slippery surfaces
MP 30x6x10 / N38

Surface type Friction coefficient / % Mocy Max load (kg/lbs/g/N)
Raw steel
µ = 0.3 30% Nominalnej Siły
6.21 kg / 13.70 LBS
6213.0 g / 60.9 N
Painted steel (standard)
µ = 0.2 20% Nominalnej Siły
4.14 kg / 9.13 LBS
4142.0 g / 40.6 N
Oily/slippery steel
µ = 0.1 10% Nominalnej Siły
2.07 kg / 4.57 LBS
2071.0 g / 20.3 N
Magnet with anti-slip rubber
µ = 0.5 50% Nominalnej Siły
10.36 kg / 22.83 LBS
10355.0 g / 101.6 N

Table 4: Steel thickness (saturation) - power losses
MP 30x6x10 / N38

Steel thickness (mm) % power Real pull force (kg/lbs/g/N)
0.5 mm
5%
1.04 kg / 2.28 LBS
1035.5 g / 10.2 N
1 mm
13%
2.59 kg / 5.71 LBS
2588.8 g / 25.4 N
2 mm
25%
5.18 kg / 11.41 LBS
5177.5 g / 50.8 N
3 mm
38%
7.77 kg / 17.12 LBS
7766.3 g / 76.2 N
5 mm
63%
12.94 kg / 28.54 LBS
12943.8 g / 127.0 N
10 mm
100%
20.71 kg / 45.66 LBS
20710.0 g / 203.2 N
11 mm
100%
20.71 kg / 45.66 LBS
20710.0 g / 203.2 N
12 mm
100%
20.71 kg / 45.66 LBS
20710.0 g / 203.2 N

Table 5: Thermal stability (stability) - thermal limit
MP 30x6x10 / N38

Ambient temp. (°C) Power loss Remaining pull (kg/lbs/g/N) Status
20 °C 0.0% 20.71 kg / 45.66 LBS
20710.0 g / 203.2 N
OK
40 °C -2.2% 20.25 kg / 44.65 LBS
20254.4 g / 198.7 N
OK
60 °C -4.4% 19.80 kg / 43.65 LBS
19798.8 g / 194.2 N
OK
80 °C -6.6% 19.34 kg / 42.64 LBS
19343.1 g / 189.8 N
100 °C -28.8% 14.75 kg / 32.51 LBS
14745.5 g / 144.7 N

Table 6: Two magnets (attraction) - forces in the system
MP 30x6x10 / N38

Gap (mm) Attraction (kg/lbs) (N-S) Sliding Force (kg/lbs/g/N) Repulsion (kg/lbs) (N-N)
0 mm 103.97 kg / 229.22 LBS
6 035 Gs
15.60 kg / 34.38 LBS
15596 g / 153.0 N
N/A
1 mm 97.15 kg / 214.17 LBS
10 864 Gs
14.57 kg / 32.13 LBS
14572 g / 143.0 N
87.43 kg / 192.75 LBS
~0 Gs
2 mm 90.42 kg / 199.35 LBS
10 481 Gs
13.56 kg / 29.90 LBS
13564 g / 133.1 N
81.38 kg / 179.42 LBS
~0 Gs
3 mm 83.97 kg / 185.13 LBS
10 100 Gs
12.60 kg / 27.77 LBS
12596 g / 123.6 N
75.57 kg / 166.61 LBS
~0 Gs
5 mm 71.94 kg / 158.60 LBS
9 349 Gs
10.79 kg / 23.79 LBS
10791 g / 105.9 N
64.75 kg / 142.74 LBS
~0 Gs
10 mm 47.34 kg / 104.36 LBS
7 583 Gs
7.10 kg / 15.65 LBS
7100 g / 69.7 N
42.60 kg / 93.92 LBS
~0 Gs
20 mm 19.03 kg / 41.96 LBS
4 809 Gs
2.86 kg / 6.29 LBS
2855 g / 28.0 N
17.13 kg / 37.77 LBS
~0 Gs
50 mm 1.53 kg / 3.37 LBS
1 363 Gs
0.23 kg / 0.51 LBS
229 g / 2.2 N
1.38 kg / 3.03 LBS
~0 Gs
60 mm 0.77 kg / 1.69 LBS
965 Gs
0.11 kg / 0.25 LBS
115 g / 1.1 N
0.69 kg / 1.52 LBS
~0 Gs
70 mm 0.41 kg / 0.90 LBS
706 Gs
0.06 kg / 0.14 LBS
61 g / 0.6 N
0.37 kg / 0.81 LBS
~0 Gs
80 mm 0.23 kg / 0.51 LBS
531 Gs
0.03 kg / 0.08 LBS
35 g / 0.3 N
0.21 kg / 0.46 LBS
~0 Gs
90 mm 0.14 kg / 0.30 LBS
409 Gs
0.02 kg / 0.05 LBS
21 g / 0.2 N
0.12 kg / 0.27 LBS
~0 Gs
100 mm 0.09 kg / 0.19 LBS
322 Gs
0.01 kg / 0.03 LBS
13 g / 0.1 N
0.08 kg / 0.17 LBS
~0 Gs

Table 7: Safety (HSE) (implants) - precautionary measures
MP 30x6x10 / N38

Object / Device Limit (Gauss) / mT Safe distance
Pacemaker 5 Gs (0.5 mT) 19.5 cm
Hearing aid 10 Gs (1.0 mT) 15.0 cm
Timepiece 20 Gs (2.0 mT) 12.0 cm
Phone / Smartphone 40 Gs (4.0 mT) 9.0 cm
Remote 50 Gs (5.0 mT) 8.5 cm
Payment card 400 Gs (40.0 mT) 3.5 cm
HDD hard drive 600 Gs (60.0 mT) 3.0 cm

Table 8: Impact energy (kinetic energy) - warning
MP 30x6x10 / N38

Start from (mm) Speed (km/h) Energy (J) Predicted outcome
10 mm 22.55 km/h
(6.26 m/s)
1.00 J
30 mm 35.40 km/h
(9.83 m/s)
2.46 J
50 mm 45.52 km/h
(12.64 m/s)
4.07 J
100 mm 64.34 km/h
(17.87 m/s)
8.13 J

Table 9: Corrosion resistance
MP 30x6x10 / 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 30x6x10 / N38

Parameter Value SI Unit / Description
Magnetic Flux 31 585 Mx 315.8 µWb
Pc Coefficient 0.96 High (Stable)

Table 11: Underwater work (magnet fishing)
MP 30x6x10 / N38

Environment Effective steel pull Effect
Air (land) 20.71 kg Standard
Water (riverbed) 23.71 kg
(+3.00 kg buoyancy gain)
+14.5%
Corrosion warning: Standard nickel requires drying after every contact with moisture; lack of maintenance will lead to rust spots.
1. Wall mount (shear)

*Note: On a vertical surface, the magnet holds only a fraction of its nominal pull.

2. Efficiency vs thickness

*Thin steel (e.g. 0.5mm PC case) significantly limits the holding force.

3. Temperature resistance

*For standard magnets, the critical limit is 80°C.

4. Demagnetization curve and operating point (B-H)

chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.96

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.

Engineering data and GPSR
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
Safety card (GPSR)
responsible entity
Dhit sp. z o.o.
ul. Kościuszki 6A, 05-850 Ożarów Mazowiecki
tel: +48 22 499 98 98 | e-mail: bok@dhit.pl
batch number/type
id: 030197-2026
Measurement Calculator
Force (pull)

Magnetic Induction

Other offers

It is ideally suited for places where solid attachment of the magnet to the substrate is required without the risk of detachment. Thanks to the hole (often for a screw), this model enables easy screwing to wood, wall, plastic, or metal. It is also often used in advertising for fixing signs and in workshops for organizing tools.
This is a crucial issue when working with model MP 30x6x10 / N38. Neodymium magnets are sintered ceramics, which means they are very brittle and inelastic. One turn too many can destroy the magnet, so do it slowly. It's a good idea to use a rubber spacer under the screw head, which will cushion the stresses. Remember: cracking during assembly results from material properties, not a product defect.
Moisture can penetrate micro-cracks in the coating and cause oxidation of the magnet. In the place of the mounting hole, the coating is thinner and can be damaged when tightening the screw, which will become a corrosion focus. If you must use it outside, paint it with anti-corrosion paint after mounting.
A screw or bolt with a thread diameter smaller than 6 mm fits this model. If the magnet does not have a chamfer (cone), we recommend using a screw with a flat or cylindrical head, or possibly using a washer. Always check that the screw head is not larger than the outer diameter of the magnet (30 mm), so it doesn't protrude beyond the outline.
It is a magnetic ring with a diameter of 30 mm and thickness 10 mm. The key parameter here is the holding force amounting to approximately 20.71 kg (force ~203.16 N). The product has a [NiCuNi] coating and is made of NdFeB material. Inner hole dimension: 6 mm.
These magnets are magnetized axially (through the thickness), which means one flat side is the N pole and the other is S. In the case of connecting two rings, make sure one is turned the right way. We do not offer paired sets with marked poles in this category, but they are easy to match manually.

Strengths and weaknesses of rare earth magnets.

Pros

Besides their tremendous field intensity, neodymium magnets offer the following advantages:
  • They have unchanged lifting capacity, and over nearly ten years their performance decreases symbolically – ~1% (in testing),
  • Neodymium magnets remain exceptionally resistant to demagnetization caused by external magnetic fields,
  • In other words, due to the smooth surface of gold, the element becomes visually attractive,
  • They show high magnetic induction at the operating surface, making them more effective,
  • Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
  • Considering the potential of accurate shaping and adaptation to custom projects, NdFeB magnets can be manufactured in a variety of geometric configurations, which makes them more universal,
  • Versatile presence in future technologies – they find application in HDD drives, drive modules, medical equipment, and multitasking production systems.
  • Thanks to efficiency per cm³, small magnets offer high operating force, in miniature format,

Limitations

What to avoid - cons of neodymium magnets and proposals for their use:
  • At strong impacts they can break, therefore we advise placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
  • NdFeB magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (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 very resistant to heat
  • When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
  • Due to limitations in realizing threads and complex shapes in magnets, we recommend using cover - magnetic holder.
  • Possible danger to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which becomes key in the context of child health protection. It is also worth noting that small components of these magnets can complicate diagnosis medical after entering the body.
  • High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

Pull force analysis

Maximum lifting capacity of the magnetwhat affects it?

The specified lifting capacity concerns the peak performance, measured under ideal test conditions, meaning:
  • using a plate made of low-carbon steel, serving as a ideal flux conductor
  • whose thickness is min. 10 mm
  • with an ideally smooth touching surface
  • under conditions of ideal adhesion (surface-to-surface)
  • during pulling in a direction perpendicular to the mounting surface
  • at temperature room level

Practical lifting capacity: influencing factors

It is worth knowing that the working load will differ influenced by elements below, in order of importance:
  • Gap (betwixt the magnet and the plate), because even a very small distance (e.g. 0.5 mm) results in a decrease in lifting capacity by up to 50% (this also applies to paint, corrosion or dirt).
  • Load vector – highest force is reached only during perpendicular pulling. The resistance to sliding of the magnet along the plate is standardly several times lower (approx. 1/5 of the lifting capacity).
  • Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of generating force.
  • Steel grade – ideal substrate is high-permeability steel. Stainless steels may attract less.
  • Surface condition – smooth surfaces guarantee perfect abutment, which increases field saturation. Rough surfaces weaken the grip.
  • Thermal factor – high temperature reduces magnetic field. Too high temperature can permanently demagnetize the magnet.

Lifting capacity testing was conducted on a smooth plate of optimal thickness, under a perpendicular pulling force, in contrast under shearing force the lifting capacity is smaller. Additionally, even a minimal clearance between the magnet’s surface and the plate lowers the lifting capacity.

Warnings
Do not give to children

Adult use only. Small elements pose a choking risk, causing severe trauma. Keep out of reach of kids and pets.

Electronic devices

Do not bring magnets near a purse, laptop, or TV. The magnetism can irreversibly ruin these devices and erase data from cards.

Fragile material

Watch out for shards. Magnets can explode upon violent connection, ejecting sharp fragments into the air. Wear goggles.

Do not drill into magnets

Powder produced during cutting of magnets is self-igniting. Do not drill into magnets unless you are an expert.

Bone fractures

Pinching hazard: The attraction force is so immense that it can result in hematomas, pinching, and broken bones. Use thick gloves.

Medical interference

For implant holders: Strong magnetic fields disrupt medical devices. Keep minimum 30 cm distance or request help to handle the magnets.

Sensitization to coating

Certain individuals experience a sensitization to Ni, which is the standard coating for NdFeB magnets. Prolonged contact may cause an allergic reaction. We suggest use safety gloves.

Immense force

Exercise caution. Neodymium magnets act from a distance and snap with huge force, often faster than you can move away.

GPS and phone interference

Be aware: rare earth magnets generate a field that disrupts sensitive sensors. Keep a separation from your phone, device, and GPS.

Power loss in heat

Control the heat. Exposing the magnet to high heat will permanently weaken its magnetic structure and pulling force.

Security! Need more info? Read our article: Are neodymium magnets dangerous?
Dhit sp. z o.o.

e-mail: bok@dhit.pl

tel: +48 888 99 98 98