Product on order Ships in 3-5 days

MP 25x7x9 / N38 - ring magnet

Name: Dhit sp. z o.o.
Address: Kościuszki 6A, Ożarów Mazowiecki, Poland, 05-850, PL
Telephone: +48 22 499 98 98
Price range: PLN 1-6500
Rating: 5

ring magnet

Catalog no 030195

GTIN/EAN: 5906301812128

5.00

Diameter

25 mm [±0,1 mm]

internal diameter Ø

7 mm [±0,1 mm]

Height

9 mm [±0,1 mm]

Weight

30.54 g

Magnetization Direction

↑ axial

Load capacity

14.82 kg / 145.39 N

Magnetic Induction

362.13 mT / 3621 Gs

Coating

[NiCuNi] Nickel

technical specifications »

12.55 ZŁ with VAT / pcs + price for transport

10.20 ZŁ net + 23% VAT / pcs

bulk discounts:

Need more?

price from 1 pcs

10.20 ZŁ

12.55 ZŁ

price from 60 pcs

9.59 ZŁ

11.79 ZŁ

price from 250 pcs

8.98 ZŁ

11.04 ZŁ

Carbon Footprint – environmental impact GPSR Regulation – product safety

Need help making a decision?

Pick up the phone and ask +48 22 499 98 98 if you prefer get in touch through request form the contact form page.
Lifting power along with form of magnetic components can be analyzed using our magnetic calculator.

Same-day processing for orders placed before 14:00.

Physical properties - MP 25x7x9 / N38 - ring magnet

Specification / characteristics - MP 25x7x9 / N38 - ring magnet

properties

properties	values
Cat. no.	030195
GTIN/EAN	5906301812128
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	25 mm [±0,1 mm]
internal diameter Ø	7 mm [±0,1 mm]
Height	9 mm [±0,1 mm]
Weight	30.54 g
Magnetization Direction	↑ axial
Load capacity ~ ?	14.82 kg / 145.39 N
Magnetic Induction ~ ?	362.13 mT / 3621 Gs
Coating	[NiCuNi] Nickel
Manufacturing Tolerance	±0.1 mm

Magnetic properties of material N38

Specification / characteristics MP 25x7x9 / 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

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 modeling of the product - report

These information represent the outcome of a mathematical simulation. Values are based on algorithms for the material Nd₂Fe₁₄B. Actual performance might slightly differ from theoretical values. Treat these calculations as a preliminary roadmap for designers.

Table 1: Static force (force vs distance) - interaction chart
MP 25x7x9 / N38

Distance (mm)	Induction (Gauss) / mT	Pull Force (kg/lbs/g/N)	Risk Status
0 mm	5777 Gs 577.7 mT	14.82 kg / 32.67 LBS 14820.0 g / 145.4 N	dangerous!
1 mm	5310 Gs 531.0 mT	12.52 kg / 27.60 LBS 12519.6 g / 122.8 N	dangerous!
2 mm	4846 Gs 484.6 mT	10.43 kg / 22.98 LBS 10425.5 g / 102.3 N	dangerous!
3 mm	4397 Gs 439.7 mT	8.59 kg / 18.93 LBS 8586.1 g / 84.2 N	strong
5 mm	3576 Gs 357.6 mT	5.68 kg / 12.52 LBS 5678.0 g / 55.7 N	strong
10 mm	2073 Gs 207.3 mT	1.91 kg / 4.21 LBS 1907.5 g / 18.7 N	safe
15 mm	1231 Gs 123.1 mT	0.67 kg / 1.48 LBS 673.1 g / 6.6 N	safe
20 mm	773 Gs 77.3 mT	0.27 kg / 0.58 LBS 265.0 g / 2.6 N	safe
30 mm	356 Gs 35.6 mT	0.06 kg / 0.12 LBS 56.2 g / 0.6 N	safe
50 mm	115 Gs 11.5 mT	0.01 kg / 0.01 LBS 5.9 g / 0.1 N	safe

Grip strength drops drastically per each millimeter of spacing. Note that even a microscopic distance (e.g., dirt, paint, veneer) strongly diminishes the holding power. Magnets hold optimally during direct contact; distance kills the force. Notice how flashily the parameters fall, when the product does not touch directly to the metal substrate. When designing the arrangement, eliminate unnecessary gaps.

Table 2: Shear capacity (wall)
MP 25x7x9 / N38

Distance (mm)	Friction coefficient	Pull Force (kg/lbs/g/N)
0 mm	Stal (~0.2)	2.96 kg / 6.53 LBS 2964.0 g / 29.1 N
1 mm	Stal (~0.2)	2.50 kg / 5.52 LBS 2504.0 g / 24.6 N
2 mm	Stal (~0.2)	2.09 kg / 4.60 LBS 2086.0 g / 20.5 N
3 mm	Stal (~0.2)	1.72 kg / 3.79 LBS 1718.0 g / 16.9 N
5 mm	Stal (~0.2)	1.14 kg / 2.50 LBS 1136.0 g / 11.1 N
10 mm	Stal (~0.2)	0.38 kg / 0.84 LBS 382.0 g / 3.7 N
15 mm	Stal (~0.2)	0.13 kg / 0.30 LBS 134.0 g / 1.3 N
20 mm	Stal (~0.2)	0.05 kg / 0.12 LBS 54.0 g / 0.5 N
30 mm	Stal (~0.2)	0.01 kg / 0.03 LBS 12.0 g / 0.1 N
50 mm	Stal (~0.2)	0.00 kg / 0.00 LBS 2.0 g / 0.0 N

The table below calculates the estimated weight limit required to initiate the downward movement of the magnet vertically along a vertical steel plate (assuming typical friction coefficient). This parameter varies with the air gap between the magnet and the metal.

Table 3: Wall mounting (shearing) - vertical pull
MP 25x7x9 / N38

Surface type	Friction coefficient / % Mocy	Max load (kg/lbs/g/N)
Raw steel	µ = 0.3 30% Nominalnej Siły	4.45 kg / 9.80 LBS 4446.0 g / 43.6 N
Painted steel (standard)	µ = 0.2 20% Nominalnej Siły	2.96 kg / 6.53 LBS 2964.0 g / 29.1 N
Oily/slippery steel	µ = 0.1 10% Nominalnej Siły	1.48 kg / 3.27 LBS 1482.0 g / 14.5 N
Magnet with anti-slip rubber	µ = 0.5 50% Nominalnej Siły	7.41 kg / 16.34 LBS 7410.0 g / 72.7 N

When placing a holder on a upright wall (e.g., a board), it will maintain barely approx. 1/5 of its maximum pull force. Gravitational force as well as a weak degree of grip cause that products move down easier than they pull off. Designing a wall mount? Remember that the shear force is significantly lower than the maximum static pull force. On a painted metal, the element will give way down under a noticeably lighter load. Application of an anti-slip pad can significantly increase the grip.

Table 4: Material efficiency (substrate influence) - sheet metal selection
MP 25x7x9 / N38

Steel thickness (mm)	% power	Real pull force (kg/lbs/g/N)
0.5 mm	5%	0.74 kg / 1.63 LBS 741.0 g / 7.3 N
1 mm	13%	1.85 kg / 4.08 LBS 1852.5 g / 18.2 N
2 mm	25%	3.71 kg / 8.17 LBS 3705.0 g / 36.3 N
3 mm	38%	5.56 kg / 12.25 LBS 5557.5 g / 54.5 N
5 mm	63%	9.26 kg / 20.42 LBS 9262.5 g / 90.9 N
10 mm	100%	14.82 kg / 32.67 LBS 14820.0 g / 145.4 N
11 mm	100%	14.82 kg / 32.67 LBS 14820.0 g / 145.4 N
12 mm	100%	14.82 kg / 32.67 LBS 14820.0 g / 145.4 N

A too thin steel is unable to absorb the entire magnetic field, which weakens actual performance of the holder. Should you install a neodymium to a too thin substrate, the magnetism will penetrate right through and the holding will be smaller. To utilize 100% of this neodymium's potential, you need a suitably thick piece of steel. The material oversaturation causes that on thin elements (e.g., thin profiles), the holder shows lower pull force. We suggest choosing the steel thickness based on the following data.

Table 5: Thermal resistance (material behavior) - resistance threshold
MP 25x7x9 / N38

Ambient temp. (°C)	Power loss	Remaining pull (kg/lbs/g/N)	Status
20 °C	0.0%	14.82 kg / 32.67 LBS 14820.0 g / 145.4 N	OK
40 °C	-2.2%	14.49 kg / 31.95 LBS 14494.0 g / 142.2 N	OK
60 °C	-4.4%	14.17 kg / 31.23 LBS 14167.9 g / 139.0 N	OK
80 °C	-6.6%	13.84 kg / 30.52 LBS 13841.9 g / 135.8 N
100 °C	-28.8%	10.55 kg / 23.26 LBS 10551.8 g / 103.5 N

Standard neodymium magnets change their properties strength above the temperature limit. Protect against heat – heat can irreversibly destroy this product. With increasing heat, the magnet's power briefly lowers. Do not use this magnet in hot environments exceeding its operating temperature limit. Exceeding the critical threshold will result in permanent loss of magnetism.

*Engineering note: Thermal stability is determined by both grade, and the Permeance Coefficient Pc. Thin magnets (low permeance coefficient) may lose charge permanently at lower temperatures than long magnets. The danger warning in the table points to a risk of irreversible loss for this specific geometry.

Table 6: Magnet-Magnet interaction (repulsion) - field collision
MP 25x7x9 / N38

Gap (mm)	Attraction (kg/lbs) (N-S)	Lateral Force (kg/lbs/g/N)	Repulsion (kg/lbs) (N-N)
0 mm	74.73 kg / 164.76 LBS 6 082 Gs	11.21 kg / 24.71 LBS 11210 g / 110.0 N	N/A
1 mm	68.86 kg / 151.81 LBS 11 091 Gs	10.33 kg / 22.77 LBS 10329 g / 101.3 N	61.97 kg / 136.63 LBS ~0 Gs
2 mm	63.13 kg / 139.18 LBS 10 620 Gs	9.47 kg / 20.88 LBS 9470 g / 92.9 N	56.82 kg / 125.26 LBS ~0 Gs
3 mm	57.70 kg / 127.20 LBS 10 153 Gs	8.65 kg / 19.08 LBS 8654 g / 84.9 N	51.93 kg / 114.48 LBS ~0 Gs
5 mm	47.77 kg / 105.31 LBS 9 238 Gs	7.17 kg / 15.80 LBS 7165 g / 70.3 N	42.99 kg / 94.78 LBS ~0 Gs
10 mm	28.63 kg / 63.12 LBS 7 152 Gs	4.29 kg / 9.47 LBS 4295 g / 42.1 N	25.77 kg / 56.81 LBS ~0 Gs
20 mm	9.62 kg / 21.21 LBS 4 145 Gs	1.44 kg / 3.18 LBS 1443 g / 14.2 N	8.66 kg / 19.09 LBS ~0 Gs
50 mm	0.59 kg / 1.29 LBS 1 024 Gs	0.09 kg / 0.19 LBS 88 g / 0.9 N	0.53 kg / 1.16 LBS ~0 Gs
60 mm	0.28 kg / 0.62 LBS 712 Gs	0.04 kg / 0.09 LBS 43 g / 0.4 N	0.26 kg / 0.56 LBS ~0 Gs
70 mm	0.15 kg / 0.33 LBS 514 Gs	0.02 kg / 0.05 LBS 22 g / 0.2 N	0.13 kg / 0.29 LBS ~0 Gs
80 mm	0.08 kg / 0.18 LBS 383 Gs	0.01 kg / 0.03 LBS 12 g / 0.1 N	0.07 kg / 0.16 LBS ~0 Gs
90 mm	0.05 kg / 0.11 LBS 293 Gs	0.01 kg / 0.02 LBS 7 g / 0.1 N	0.04 kg / 0.10 LBS ~0 Gs
100 mm	0.03 kg / 0.07 LBS 230 Gs	0.00 kg / 0.01 LBS 4 g / 0.0 N	0.03 kg / 0.06 LBS ~0 Gs

Two magnets interact from a significantly greater distance than a magnet and sheet setup. Such a system of magnet-to-magnet produces a massive flux and a further horizon of action. Want to build a powerful holder? Use a pair of magnets instead of one magnet and a striker plate. Be careful that when bringing together two magnets, the impact force is extreme. The levitation is marginally weaker than the attraction, but still large.
*Flux density for N-N configuration is approximately ~0 Gs at the geometric center of the gap (caused by magnetic field nullification).
* Figures show shear force of dual same neodymium magnets (friction ~0.15 for Ni-Ni layer).

Table 7: Hazards (electronics) - warnings
MP 25x7x9 / N38

Object / Device	Limit (Gauss) / mT	Safe distance
Pacemaker	5 Gs (0.5 mT)	17.0 cm
Hearing aid	10 Gs (1.0 mT)	13.5 cm
Timepiece	20 Gs (2.0 mT)	10.5 cm
Phone / Smartphone	40 Gs (4.0 mT)	8.0 cm
Car key	50 Gs (5.0 mT)	7.5 cm
Payment card	400 Gs (40.0 mT)	3.0 cm
HDD hard drive	600 Gs (60.0 mT)	2.5 cm

Extremely neodym field is a real danger to electronic devices and medical implants. These neodymiums produce a flux that destroys function of digital equipment. Be aware: the unseen radiation penetrates the body and plastic. Exceptional care must be taken by people with hearing aids and insulin pumps. Also at risk are: mechanical watches, car keys, membranes, and screens. Avoid contact with magnetic cards, HDD media, or sensitive navigation tools.

Table 8: Collisions (kinetic energy) - warning
MP 25x7x9 / N38

Start from (mm)	Speed (km/h)	Energy (J)
10 mm	23.94 km/h (6.65 m/s)	0.68 J
30 mm	38.57 km/h (10.71 m/s)	1.75 J
50 mm	49.69 km/h (13.80 m/s)	2.91 J
100 mm	70.25 km/h (19.52 m/s)	5.82 J

Neodymium magnets are prone to chipping – a strong collision with metal causes immediate chipping. Pay attention to connection velocity – a magnet released freely becomes dangerous. Impact energy can trigger coating fragments or injury to skin. Always hold the magnet during bringing near metal so it doesn't slam with momentum against the metal. A collision at high speed means shattering of the neodymium. Use safety goggles when working with large magnets.

Table 9: Surface protection spec
MP 25x7x9 / 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)

For outdoor applications, an epoxy coating is required; standard nickel is intended for indoor use. Moisture resistance is crucial for installations in bathrooms or outdoors.

Table 10: Construction data (P_c)
MP 25x7x9 / N38

Parameter	Value	SI Unit / Description
Magnetic Flux	22 495 Mx	225.0 µWb
P_c Coefficient	1.05	High (Stable)

Flux value emitted by the magnet pole. Key data for generator designers as well as sensors. P_c value defines the working geometry.

Table 11: Hydrostatics and buoyancy
MP 25x7x9 / N38

Environment	Effective steel pull	Effect
Air (land)	14.82 kg	Standard
Water (riverbed)	16.97 kg (+2.15 kg buoyancy gain)	+14.5%

Corrosion warning: Remember to wipe the magnet thoroughly after removing it from water and apply a protective layer (e.g., oil) to avoid corrosion.

In water, the magnet feels stronger thanks to Archimedes' principle. Buoyancy helps in lifting finds.

1. Sliding resistance

*Warning: On a vertical surface, the magnet retains just ~20% of its nominal pull.

2. Efficiency vs thickness

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

3. Heat tolerance

*For N38 material, the max working temp is 80°C.

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

chart generated for the permeance coefficient P_c (Permeance Coefficient) = 1.05

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 P_c (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 P_c 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%

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: 030195-2026

Magnet Unit Converter

Pulling force

Kilograms (kg)

Newtons (N)

lbs

Magnetic Field

Induction (Gs)

Put a figure in a single slot to generate results for the other units right away.

Other proposals

Product on order Ships in 3-5 days

SM 25x175 [2xM8] / N52 - magnetic separator

541.20 ZŁ brutto / pcs

Product on order Ships in 3-5 days

UMS 42x12.5x6.5x9 / N38 - conical magnetic holder

27.06 ZŁ brutto / pcs

Product on order Ships in 3-5 days

MT 50x1.5x100000 - magnetic tape

861.00 ZŁ brutto / pcs

Product on order Ships in 3-5 days

UMGZ 25x17x8 [M5] GZ / N38 - magnetic holder external thread

12.23 ZŁ brutto / pcs

It is ideally suited for places where solid attachment of the magnet to the substrate is required without the risk of detachment. Mounting is clean and reversible, unlike gluing. It is also often used in advertising for fixing signs and in workshops for organizing tools.

This material behaves more like porcelain than steel, so it doesn't forgive mistakes during mounting. When tightening the screw, you must maintain great sensitivity. We recommend tightening manually with a screwdriver, not an impact driver, because excessive force will cause the ring to crack. 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.

These magnets are coated with standard Ni-Cu-Ni plating, which protects them in indoor conditions, but is not sufficient for rain. In the place of the mounting hole, the coating is thinner and easily scratched when tightening the screw, which will become a corrosion focus. This product is dedicated for inside building use. For outdoor applications, we recommend choosing magnets in hermetic housing or additional protection with varnish.

A screw or bolt with a thread diameter smaller than 7 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. Aesthetic mounting requires selecting the appropriate head size.

This model is characterized by dimensions Ø25x9 mm and a weight of 30.54 g. The key parameter here is the lifting capacity amounting to approximately 14.82 kg (force ~145.39 N). The product has a [NiCuNi] coating and is made of NdFeB material. Inner hole dimension: 7 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 rare earth magnets.

Strengths

Besides their durability, neodymium magnets are valued for these benefits:

They do not lose magnetism, even during approximately ten years – the decrease in lifting capacity is only ~1% (according to tests),
They are noted for resistance to demagnetization induced by presence of other magnetic fields,
The use of an aesthetic finish of noble metals (nickel, gold, silver) causes the element to present itself better,
Magnetic induction on the working part of the magnet turns out to be very high,
Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and are able to act (depending on the shape) even at a temperature of 230°C or more...
Thanks to the potential of accurate molding and adaptation to specialized projects, magnetic components can be modeled in a broad palette of forms and dimensions, which expands the range of possible applications,
Wide application in modern technologies – they are commonly used in data components, electric drive systems, medical devices, as well as technologically advanced constructions.
Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Weaknesses

Disadvantages of NdFeB magnets:

To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as 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 start to rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
We suggest casing - magnetic holder, 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 aspect of protecting the youngest. Additionally, small components of these magnets are able to disrupt the diagnostic process medical in case of swallowing.
With budget limitations the cost of neodymium magnets can be a barrier,

Pull force analysis

Detachment force of the magnet in optimal conditions – what it depends on?

Magnet power was defined for the most favorable conditions, taking into account:

using a plate made of low-carbon steel, serving as a magnetic yoke
with a cross-section no less than 10 mm
characterized by smoothness
with zero gap (no coatings)
for force acting at a right angle (in the magnet axis)
at conditions approx. 20°C

Magnet lifting force in use – key factors

It is worth knowing that the application force may be lower influenced by elements below, starting with the most relevant:

Distance – existence of foreign body (paint, dirt, air) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
Angle of force application – maximum parameter is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the plate is standardly several times lower (approx. 1/5 of the lifting capacity).
Element thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
Steel type – low-carbon steel gives the best results. Higher carbon content decrease magnetic properties and lifting capacity.
Smoothness – full contact is obtained only on smooth steel. Rough texture create air cushions, reducing force.
Thermal factor – high temperature reduces pulling force. Too high temperature can permanently demagnetize the magnet.

Lifting capacity was determined by applying a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under shearing force the lifting capacity is smaller. Additionally, even a minimal clearance between the magnet’s surface and the plate reduces the holding force.

H&S for magnets

Hand protection

Protect your hands. Two large magnets will snap together immediately with a force of massive weight, crushing everything in their path. Be careful!

Impact on smartphones

Navigation devices and smartphones are highly susceptible to magnetic fields. Close proximity with a powerful NdFeB magnet can permanently damage the internal compass in your phone.

Power loss in heat

Regular neodymium magnets (grade N) undergo demagnetization when the temperature exceeds 80°C. This process is irreversible.

Data carriers

Powerful magnetic fields can erase data on credit cards, hard drives, and storage devices. Stay away of at least 10 cm.

Nickel coating and allergies

A percentage of the population suffer from a hypersensitivity to Ni, which is the common plating for neodymium magnets. Prolonged contact might lead to an allergic reaction. We strongly advise wear protective gloves.

Magnets are brittle

Neodymium magnets are sintered ceramics, which means they are prone to chipping. Collision of two magnets will cause them shattering into shards.

Adults only

Adult use only. Tiny parts can be swallowed, leading to intestinal necrosis. Store away from kids and pets.

Fire warning

Powder generated during machining of magnets is flammable. Do not drill into magnets without proper cooling and knowledge.

Do not underestimate power

Use magnets with awareness. Their powerful strength can surprise even experienced users. Be vigilant and respect their power.

Pacemakers

Life threat: Strong magnets can turn off heart devices and defibrillators. Stay away if you have medical devices.

Caution! Details about hazards in the article: Safety of working with magnets.

MP 25x7x9 / N38 - ring magnet

Physical properties - MP 25x7x9 / N38 - ring magnet

Magnetic properties of material N38

Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C

Technical modeling of the product - report

Table 1: Static force (force vs distance) - interaction chart MP 25x7x9 / N38

Table 2: Shear capacity (wall) MP 25x7x9 / N38

Table 3: Wall mounting (shearing) - vertical pull MP 25x7x9 / N38

Table 4: Material efficiency (substrate influence) - sheet metal selection MP 25x7x9 / N38

Table 5: Thermal resistance (material behavior) - resistance threshold MP 25x7x9 / N38

Table 6: Magnet-Magnet interaction (repulsion) - field collision MP 25x7x9 / N38

Table 7: Hazards (electronics) - warnings MP 25x7x9 / N38

Table 8: Collisions (kinetic energy) - warning MP 25x7x9 / N38

Table 9: Surface protection spec MP 25x7x9 / N38

Table 10: Construction data (Pc) MP 25x7x9 / N38

Table 11: Hydrostatics and buoyancy MP 25x7x9 / N38

1. Sliding resistance

2. Efficiency vs thickness

3. Heat tolerance

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

Material specification

Ecology and recycling (GPSR)

Pulling force

Magnetic Field

Other proposals

SM 25x175 [2xM8] / N52 - magnetic separator

UMS 42x12.5x6.5x9 / N38 - conical magnetic holder

MT 50x1.5x100000 - magnetic tape

UMGZ 25x17x8 [M5] GZ / N38 - magnetic holder external thread

Strengths and weaknesses of rare earth magnets.

Strengths

Weaknesses

Pull force analysis

Detachment force of the magnet in optimal conditions – what it depends on?

Magnet lifting force in use – key factors

H&S for magnets

Hand protection

Impact on smartphones

Power loss in heat

Data carriers

Nickel coating and allergies

Magnets are brittle

Adults only

Fire warning

Do not underestimate power

Pacemakers

Physical properties of sintered neodymium magnets Nd₂Fe₁₄B at 20°C

Table 1: Static force (force vs distance) - interaction chart
MP 25x7x9 / N38

Table 2: Shear capacity (wall)
MP 25x7x9 / N38

Table 3: Wall mounting (shearing) - vertical pull
MP 25x7x9 / N38

Table 4: Material efficiency (substrate influence) - sheet metal selection
MP 25x7x9 / N38

Table 5: Thermal resistance (material behavior) - resistance threshold
MP 25x7x9 / N38

Table 6: Magnet-Magnet interaction (repulsion) - field collision
MP 25x7x9 / N38

Table 7: Hazards (electronics) - warnings
MP 25x7x9 / N38

Table 8: Collisions (kinetic energy) - warning
MP 25x7x9 / N38

Table 9: Surface protection spec
MP 25x7x9 / N38

Table 10: Construction data (P_c)
MP 25x7x9 / N38

Table 11: Hydrostatics and buoyancy
MP 25x7x9 / N38