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MP 8x6/3.5x3 / N38 - ring magnet

ring magnet

Catalog no 030206

GTIN/EAN: 5906301812234

5.00
Load capacity 1.37 kg / 13.48 N Magnetic Induction 371.53 mT / 3715 Gs
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

0.570net / pcs

0.701 zł with VAT (23% VAT) / pcs

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Gross
price from 1 pcs
0.570 zł
0.701 zł
price from 1100 pcs
0.536 zł
0.659 zł
price from 4400 pcs
0.502 zł
0.617 zł

Frequently asked questions

What is the hole in a ring magnet for?
For mounting on a screw or a shaft. The bore may be cylindrical or countersunk for a screw head. The hole removes magnet volume, so a ring holds less than a disc of the same outside diameter.
What is the polarisation?
Axial as standard — poles on the flat faces of the ring. Diametrical polarisation is made to order.
What sizes are available?
Outside diameter from 5 to 62 mm from stock. To order up to 200 mm outside diameter, 180 mm bore and 40 mm height, with a lead time of 25–35 days.

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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Call us now +48 888 99 98 98 alternatively let us know using contact form the contact section.
Specifications and structure of a neodymium magnet can be estimated using our power calculator.

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Technical details - MP 8x6/3.5x3 / N38 - ring magnet

Specification / characteristics - MP 8x6/3.5x3 / N38 - ring magnet

properties
properties values
Cat. no. 030206
GTIN/EAN 5906301812234
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 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

Specification / characteristics MP 8x6/3.5x3 / N38 - ring magnet
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

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
10%
0.14 kg / 0.30 LBS
137.0 g / 1.3 N
1 mm
25%
0.34 kg / 0.76 LBS
342.5 g / 3.4 N
2 mm
50%
0.69 kg / 1.51 LBS
685.0 g / 6.7 N
3 mm
75%
1.03 kg / 2.27 LBS
1027.5 g / 10.1 N
5 mm
100%
1.37 kg / 3.02 LBS
1370.0 g / 13.4 N
10 mm
100%
1.37 kg / 3.02 LBS
1370.0 g / 13.4 N
11 mm
100%
1.37 kg / 3.02 LBS
1370.0 g / 13.4 N
12 mm
100%
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%
Warning: Remember to wipe the magnet thoroughly after removing it from water and apply a protective layer (e.g., oil) to avoid corrosion.

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.

Technical specification and ecology

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
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: 030206-2026
Magnet Unit Converter

Pulling force


Magnetic Induction

Check out also proposals

The ring magnet with a hole MP 8x6/3.5x3 / N38 is created for mechanical fastening, where glue might fail or be insufficient. Thanks to the hole (often for a screw), this model enables quick installation to wood, wall, plastic, or metal. This product with a force of 1.37 kg works great as a door latch, speaker holder, or mounting element in devices.
This is a crucial issue when working with model MP 8x6/3.5x3 / N38. Neodymium magnets are sintered ceramics, which means they are hard but breakable and inelastic. One turn too many can destroy the magnet, so do it slowly. The flat screw head should evenly press the magnet. 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.
The inner hole diameter determines the maximum size of the mounting element. 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 (8 mm), so it doesn't protrude beyond the outline.
It is a magnetic ring with a diameter of 8 mm and thickness 3 mm. The key parameter here is the holding force amounting to approximately 1.37 kg (force ~13.48 N). The product has a [NiCuNi] coating and is made of NdFeB material. Inner hole dimension: 6/3.5 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.

Pros as well as cons of rare earth magnets.

Strengths

Besides their tremendous strength, neodymium magnets offer the following advantages:
  • 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

Disadvantages of NdFeB magnets:
  • 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 magnetwhat contributes to it?

Magnet power was defined for ideal contact conditions, taking into account:
  • 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

Effective lifting capacity is influenced by working environment parameters, including (from priority):
  • 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.

Danger! Details about hazards in the article: Magnet Safety Guide.