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MP 62x42x25 / N38 - ring magnet

ring magnet

Catalog no 030205

GTIN/EAN: 5906301812227

5.00
Load capacity 58.67 kg / 575.60 N Magnetic Induction 389.14 mT / 3891 Gs
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
Coating
[NiCuNi] Nickel

How we measure these parameters — certificates and measurements

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Net
Gross
price from 1 pcs
134.15 zł
165.00 zł
price from 5 pcs
126.10 zł
155.10 zł
price from 20 pcs
118.05 zł
145.20 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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Specifications and structure of a neodymium magnet can be estimated using our power calculator.

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Technical data - MP 62x42x25 / N38 - ring magnet

Specification / characteristics - MP 62x42x25 / N38 - ring magnet

properties
properties values
Cat. no. 030205
GTIN/EAN 5906301812227
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 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

Specification / characteristics MP 62x42x25 / 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

Engineering modeling of the magnet - data

Presented values represent the outcome of a mathematical calculation. Values were calculated on algorithms for the class Nd2Fe14B. Operational parameters might slightly differ. Use these calculations as a preliminary roadmap during assembly planning.

Table 1: Static force (force vs distance) - 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 pounds
58670.0 g / 575.6 N
dangerous!
1 mm 4338 Gs
433.8 mT
55.21 kg / 121.72 pounds
55213.2 g / 541.6 N
dangerous!
2 mm 4201 Gs
420.1 mT
51.77 kg / 114.13 pounds
51768.5 g / 507.8 N
dangerous!
3 mm 4061 Gs
406.1 mT
48.39 kg / 106.69 pounds
48394.9 g / 474.8 N
dangerous!
5 mm 3781 Gs
378.1 mT
41.94 kg / 92.47 pounds
41942.4 g / 411.5 N
dangerous!
10 mm 3097 Gs
309.7 mT
28.15 kg / 62.06 pounds
28148.0 g / 276.1 N
dangerous!
15 mm 2485 Gs
248.5 mT
18.12 kg / 39.94 pounds
18118.5 g / 177.7 N
dangerous!
20 mm 1972 Gs
197.2 mT
11.41 kg / 25.16 pounds
11412.7 g / 112.0 N
dangerous!
30 mm 1239 Gs
123.9 mT
4.51 kg / 9.93 pounds
4505.2 g / 44.2 N
medium risk
50 mm 533 Gs
53.3 mT
0.83 kg / 1.84 pounds
832.4 g / 8.2 N
low risk

Table 2: Sliding 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 pounds
11734.0 g / 115.1 N
1 mm Stal (~0.2) 11.04 kg / 24.34 pounds
11042.0 g / 108.3 N
2 mm Stal (~0.2) 10.35 kg / 22.83 pounds
10354.0 g / 101.6 N
3 mm Stal (~0.2) 9.68 kg / 21.34 pounds
9678.0 g / 94.9 N
5 mm Stal (~0.2) 8.39 kg / 18.49 pounds
8388.0 g / 82.3 N
10 mm Stal (~0.2) 5.63 kg / 12.41 pounds
5630.0 g / 55.2 N
15 mm Stal (~0.2) 3.62 kg / 7.99 pounds
3624.0 g / 35.6 N
20 mm Stal (~0.2) 2.28 kg / 5.03 pounds
2282.0 g / 22.4 N
30 mm Stal (~0.2) 0.90 kg / 1.99 pounds
902.0 g / 8.8 N
50 mm Stal (~0.2) 0.17 kg / 0.37 pounds
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 pounds
17601.0 g / 172.7 N
Painted steel (standard)
µ = 0.2 20% Nominalnej Siły
11.73 kg / 25.87 pounds
11734.0 g / 115.1 N
Oily/slippery steel
µ = 0.1 10% Nominalnej Siły
5.87 kg / 12.93 pounds
5867.0 g / 57.6 N
Magnet with anti-slip rubber
µ = 0.5 50% Nominalnej Siły
29.34 kg / 64.67 pounds
29335.0 g / 287.8 N

Table 4: Steel thickness (saturation) - sheet metal selection
MP 62x42x25 / N38

Steel thickness (mm) % power Real pull force (kg/lbs/g/N)
0.5 mm
3%
1.96 kg / 4.31 pounds
1955.7 g / 19.2 N
1 mm
8%
4.89 kg / 10.78 pounds
4889.2 g / 48.0 N
2 mm
17%
9.78 kg / 21.56 pounds
9778.3 g / 95.9 N
3 mm
25%
14.67 kg / 32.34 pounds
14667.5 g / 143.9 N
5 mm
42%
24.45 kg / 53.89 pounds
24445.8 g / 239.8 N
10 mm
83%
48.89 kg / 107.79 pounds
48891.7 g / 479.6 N
11 mm
92%
53.78 kg / 118.57 pounds
53780.8 g / 527.6 N
12 mm
100%
58.67 kg / 129.35 pounds
58670.0 g / 575.6 N

Table 5: Thermal stability (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 pounds
58670.0 g / 575.6 N
OK
40 °C -2.2% 57.38 kg / 126.50 pounds
57379.3 g / 562.9 N
OK
60 °C -4.4% 56.09 kg / 123.65 pounds
56088.5 g / 550.2 N
OK
80 °C -6.6% 54.80 kg / 120.81 pounds
54797.8 g / 537.6 N
100 °C -28.8% 41.77 kg / 92.09 pounds
41773.0 g / 409.8 N

Table 6: Two magnets (attraction) - field range
MP 62x42x25 / N38

Gap (mm) Attraction (kg/lbs) (N-S) Shear Force (kg/lbs/g/N) Repulsion (kg/lbs) (N-N)
0 mm 264.93 kg / 584.07 pounds
5 588 Gs
39.74 kg / 87.61 pounds
39740 g / 389.8 N
N/A
1 mm 257.19 kg / 567.00 pounds
8 812 Gs
38.58 kg / 85.05 pounds
38578 g / 378.4 N
231.47 kg / 510.30 pounds
~0 Gs
2 mm 249.32 kg / 549.66 pounds
8 676 Gs
37.40 kg / 82.45 pounds
37398 g / 366.9 N
224.39 kg / 494.69 pounds
~0 Gs
3 mm 241.51 kg / 532.44 pounds
8 539 Gs
36.23 kg / 79.87 pounds
36227 g / 355.4 N
217.36 kg / 479.19 pounds
~0 Gs
5 mm 226.10 kg / 498.47 pounds
8 262 Gs
33.92 kg / 74.77 pounds
33915 g / 332.7 N
203.49 kg / 448.62 pounds
~0 Gs
10 mm 189.40 kg / 417.55 pounds
7 562 Gs
28.41 kg / 62.63 pounds
28409 g / 278.7 N
170.46 kg / 375.79 pounds
~0 Gs
20 mm 127.11 kg / 280.22 pounds
6 195 Gs
19.07 kg / 42.03 pounds
19066 g / 187.0 N
114.40 kg / 252.20 pounds
~0 Gs
50 mm 32.28 kg / 71.17 pounds
3 122 Gs
4.84 kg / 10.68 pounds
4843 g / 47.5 N
29.06 kg / 64.06 pounds
~0 Gs
60 mm 20.34 kg / 44.85 pounds
2 478 Gs
3.05 kg / 6.73 pounds
3052 g / 29.9 N
18.31 kg / 40.36 pounds
~0 Gs
70 mm 12.99 kg / 28.63 pounds
1 980 Gs
1.95 kg / 4.29 pounds
1948 g / 19.1 N
11.69 kg / 25.77 pounds
~0 Gs
80 mm 8.43 kg / 18.59 pounds
1 595 Gs
1.26 kg / 2.79 pounds
1265 g / 12.4 N
7.59 kg / 16.73 pounds
~0 Gs
90 mm 5.58 kg / 12.29 pounds
1 298 Gs
0.84 kg / 1.84 pounds
836 g / 8.2 N
5.02 kg / 11.06 pounds
~0 Gs
100 mm 3.76 kg / 8.29 pounds
1 065 Gs
0.56 kg / 1.24 pounds
564 g / 5.5 N
3.38 kg / 7.46 pounds
~0 Gs

Table 7: Safety (HSE) (electronics) - 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
Mobile device 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: Collisions (kinetic energy) - collision effects
MP 62x42x25 / N38

Start from (mm) Speed (km/h) Energy (J) Predicted outcome
10 mm 18.77 km/h
(5.21 m/s)
4.16 J
30 mm 23.85 km/h
(6.63 m/s)
6.72 J
50 mm 24.58 km/h
(6.83 m/s)
7.14 J
100 mm 24.78 km/h
(6.88 m/s)
7.26 J

Table 9: Coating parameters (durability)
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%
Rust risk: Standard nickel requires drying after every contact with moisture; lack of maintenance will lead to rust spots.

1. Vertical hold

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

2. Steel saturation

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

3. Power loss vs temp

*For N38 grade, the critical limit is 80°C.

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

chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.64

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

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: 030205-2026
Measurement Calculator

Pulling force


Magnetic Induction

Other offers

The ring-shaped magnet MP 62x42x25 / N38 is created for permanent mounting, where glue might fail or be insufficient. Mounting is clean and reversible, unlike gluing. This product with a force of 58.67 kg works great as a cabinet closure, speaker holder, or spacer element in devices.
This is a crucial issue when working with model MP 62x42x25 / 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. 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 42 mm fits this model. For magnets with a straight hole, a conical head can act like a wedge and burst the magnet. Aesthetic mounting requires selecting the appropriate head size.
The presented product is a ring magnet with dimensions Ø62 mm (outer diameter) and height 25 mm. The key parameter here is the holding force amounting to approximately 58.67 kg (force ~575.60 N). The product has a [NiCuNi] coating and is made of NdFeB material. Inner hole dimension: 42 mm.
The poles are located on the planes with holes, not on the sides of the ring. If you want two such magnets screwed with cones facing each other (faces) to attract, you must connect them with opposite poles (N to S). We do not offer paired sets with marked poles in this category, but they are easy to match manually.

Strengths and weaknesses of Nd2Fe14B magnets.

Advantages

In addition to their long-term stability, neodymium magnets provide the following advantages:
  • They do not lose magnetism, even over approximately ten years – the reduction in strength is only ~1% (according to tests),
  • They show high resistance to demagnetization induced by external magnetic fields,
  • Thanks to the glossy finish, the plating of nickel, gold, or silver gives an professional appearance,
  • They are known for high magnetic induction at the operating surface, making them more effective,
  • Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
  • Thanks to freedom in shaping and the capacity to adapt to complex applications,
  • Wide application in advanced technology sectors – they serve a role in computer drives, drive modules, medical devices, also technologically advanced constructions.
  • Thanks to their power density, small magnets offer high operating force, in miniature format,

Limitations

Disadvantages of neodymium magnets:
  • To avoid cracks under impact, we recommend using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
  • We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
  • They oxidize in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
  • Limited ability of producing threads in the magnet and complicated shapes - preferred is cover - mounting mechanism.
  • Potential hazard resulting from small fragments of magnets pose a threat, if swallowed, which is particularly important in the context of child safety. It is also worth noting that small components of these devices can disrupt the diagnostic process medical in case of swallowing.
  • With mass production the cost of neodymium magnets is a challenge,

Pull force analysis

Maximum lifting capacity of the magnetwhat affects it?

The force parameter is a result of laboratory testing performed under the following configuration:
  • with the application of a yoke made of low-carbon steel, guaranteeing maximum field concentration
  • whose transverse dimension reaches at least 10 mm
  • with an polished contact surface
  • with zero gap (without impurities)
  • under axial force direction (90-degree angle)
  • at temperature approx. 20 degrees Celsius

Key elements affecting lifting force

It is worth knowing that the magnet holding may be lower depending on elements below, in order of importance:
  • Distance (betwixt the magnet and the metal), because even a microscopic distance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
  • Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet exhibits much less (typically approx. 20-30% of nominal force).
  • Element thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet restricts the attraction force (the magnet "punches through" it).
  • Material composition – different alloys reacts the same. Alloy additives worsen the attraction effect.
  • Plate texture – smooth surfaces guarantee perfect abutment, which improves field saturation. Rough surfaces reduce efficiency.
  • Operating temperature – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures gain strength (up to a certain limit).

Holding force was tested on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under shearing force the lifting capacity is smaller. Moreover, even a slight gap between the magnet and the plate decreases the lifting capacity.

H&S for magnets
GPS Danger

A powerful magnetic field interferes with the functioning of compasses in phones and GPS navigation. Do not bring magnets near a device to prevent breaking the sensors.

No play value

Strictly keep magnets away from children. Risk of swallowing is high, and the effects of magnets connecting inside the body are tragic.

Life threat

Life threat: Neodymium magnets can deactivate heart devices and defibrillators. Stay away if you have electronic implants.

Avoid contact if allergic

Certain individuals have a contact allergy to nickel, which is the common plating for NdFeB magnets. Extended handling might lead to an allergic reaction. It is best to use protective gloves.

Respect the power

Use magnets consciously. Their powerful strength can shock even professionals. Be vigilant and do not underestimate their power.

Shattering risk

Protect your eyes. Magnets can fracture upon violent connection, ejecting sharp fragments into the air. Wear goggles.

Heat warning

Standard neodymium magnets (N-type) lose magnetization when the temperature exceeds 80°C. Damage is permanent.

Dust is flammable

Mechanical processing of NdFeB material poses a fire risk. Neodymium dust oxidizes rapidly with oxygen and is difficult to extinguish.

Safe distance

Do not bring magnets near a purse, laptop, or TV. The magnetism can permanently damage these devices and wipe information from cards.

Pinching danger

Watch your fingers. Two powerful magnets will join immediately with a force of massive weight, crushing anything in their path. Be careful!

Security! Looking for details? Check our post: Why are neodymium magnets dangerous?