Product available Ships today (order by 14:00)

MP 40x20x5 / 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 030199

GTIN/EAN: 5906301812166

5.00

Diameter

40 mm [±0,1 mm]

internal diameter Ø

20 mm [±0,1 mm]

Height

5 mm [±0,1 mm]

Weight

35.34 g

Magnetization Direction

↑ axial

Load capacity

7.24 kg / 70.98 N

Magnetic Induction

150.36 mT / 1504 Gs

Coating

[NiCuNi] Nickel

technical details »

12.24 ZŁ with VAT / pcs + price for transport

9.95 ZŁ net + 23% VAT / pcs

bulk discounts:

Need more?

price from 1 pcs

9.95 ZŁ

12.24 ZŁ

price from 100 pcs

9.35 ZŁ

11.50 ZŁ

price from 300 pcs

8.76 ZŁ

10.77 ZŁ

Carbon Footprint – environmental impact GPSR Regulation – product safety

Looking for a better price?

Call us now +48 22 499 98 98 if you prefer send us a note by means of form our website.
Strength as well as shape of neodymium magnets can be estimated with our force calculator.

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

Product card - MP 40x20x5 / N38 - ring magnet

Specification / characteristics - MP 40x20x5 / N38 - ring magnet

properties

properties	values
Cat. no.	030199
GTIN/EAN	5906301812166
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	40 mm [±0,1 mm]
internal diameter Ø	20 mm [±0,1 mm]
Height	5 mm [±0,1 mm]
Weight	35.34 g
Magnetization Direction	↑ axial
Load capacity ~ ?	7.24 kg / 70.98 N
Magnetic Induction ~ ?	150.36 mT / 1504 Gs
Coating	[NiCuNi] Nickel
Manufacturing Tolerance	±0.1 mm

Magnetic properties of material N38

Specification / characteristics MP 40x20x5 / 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

Physical simulation of the assembly - technical parameters

Presented values are the result of a mathematical calculation. Results are based on models for the material Nd₂Fe₁₄B. Actual conditions might slightly differ. Treat these calculations as a supplementary guide for designers.

Table 1: Static force (force vs gap) - power drop
MP 40x20x5 / N38

Distance (mm)	Induction (Gauss) / mT	Pull Force (kg/lbs/g/N)	Risk Status
0 mm	5269 Gs 526.9 mT	7.24 kg / 15.96 LBS 7240.0 g / 71.0 N	medium risk
1 mm	5005 Gs 500.5 mT	6.53 kg / 14.41 LBS 6534.7 g / 64.1 N	medium risk
2 mm	4739 Gs 473.9 mT	5.86 kg / 12.91 LBS 5857.7 g / 57.5 N	medium risk
3 mm	4475 Gs 447.5 mT	5.22 kg / 11.51 LBS 5222.2 g / 51.2 N	medium risk
5 mm	3960 Gs 396.0 mT	4.09 kg / 9.02 LBS 4090.8 g / 40.1 N	medium risk
10 mm	2832 Gs 283.2 mT	2.09 kg / 4.61 LBS 2092.3 g / 20.5 N	medium risk
15 mm	1990 Gs 199.0 mT	1.03 kg / 2.28 LBS 1033.4 g / 10.1 N	safe
20 mm	1407 Gs 140.7 mT	0.52 kg / 1.14 LBS 516.3 g / 5.1 N	safe
30 mm	745 Gs 74.5 mT	0.14 kg / 0.32 LBS 144.6 g / 1.4 N	safe
50 mm	268 Gs 26.8 mT	0.02 kg / 0.04 LBS 18.7 g / 0.2 N	safe

Pulling power drops significantly with every mm of spacing. Keep in mind that even the smallest gap (e.g., dirt, paint, veneer) strongly reduces the pull force. Neodymiums operate most effectively at the point of direct contact; air break nullifies the force. Observe how quickly the parameters drop, when the magnet does not touch directly to the steel surface. When designing the mounting, eliminate additional spacers.

Table 2: Vertical hold (wall)
MP 40x20x5 / N38

Distance (mm)	Friction coefficient	Pull Force (kg/lbs/g/N)
0 mm	Stal (~0.2)	1.45 kg / 3.19 LBS 1448.0 g / 14.2 N
1 mm	Stal (~0.2)	1.31 kg / 2.88 LBS 1306.0 g / 12.8 N
2 mm	Stal (~0.2)	1.17 kg / 2.58 LBS 1172.0 g / 11.5 N
3 mm	Stal (~0.2)	1.04 kg / 2.30 LBS 1044.0 g / 10.2 N
5 mm	Stal (~0.2)	0.82 kg / 1.80 LBS 818.0 g / 8.0 N
10 mm	Stal (~0.2)	0.42 kg / 0.92 LBS 418.0 g / 4.1 N
15 mm	Stal (~0.2)	0.21 kg / 0.45 LBS 206.0 g / 2.0 N
20 mm	Stal (~0.2)	0.10 kg / 0.23 LBS 104.0 g / 1.0 N
30 mm	Stal (~0.2)	0.03 kg / 0.06 LBS 28.0 g / 0.3 N
50 mm	Stal (~0.2)	0.00 kg / 0.01 LBS 4.0 g / 0.0 N

The following data calculates the approximate shear load sufficient to cause the shifting of the magnet vertically on a vertical steel plate (considering standard friction coefficient). This value is a function of the air gap between the magnet and the metal.

Table 3: Wall mounting (sliding) - behavior on slippery surfaces
MP 40x20x5 / N38

Surface type	Friction coefficient / % Mocy	Max load (kg/lbs/g/N)
Raw steel	µ = 0.3 30% Nominalnej Siły	2.17 kg / 4.79 LBS 2172.0 g / 21.3 N
Painted steel (standard)	µ = 0.2 20% Nominalnej Siły	1.45 kg / 3.19 LBS 1448.0 g / 14.2 N
Oily/slippery steel	µ = 0.1 10% Nominalnej Siły	0.72 kg / 1.60 LBS 724.0 g / 7.1 N
Magnet with anti-slip rubber	µ = 0.5 50% Nominalnej Siły	3.62 kg / 7.98 LBS 3620.0 g / 35.5 N

When hanging a magnet on a vertical plane (e.g., a board), it will only hold only approx. 1/5 of nominal attraction strength. Gravity as well as a weak degree of grip influence the fact that magnets move down faster than they detach. Planning a vertical fastening? Note that the sliding force is noticeably lower than the maximum static pull force. On a painted metal, the element will give way down under a significantly smaller cargo. Using a rubber coating can effectively raise the stability.

Table 4: Steel thickness (substrate influence) - sheet metal selection
MP 40x20x5 / N38

Steel thickness (mm)	% power	Real pull force (kg/lbs/g/N)
0.5 mm	10%	0.72 kg / 1.60 LBS 724.0 g / 7.1 N
1 mm	25%	1.81 kg / 3.99 LBS 1810.0 g / 17.8 N
2 mm	50%	3.62 kg / 7.98 LBS 3620.0 g / 35.5 N
3 mm	75%	5.43 kg / 11.97 LBS 5430.0 g / 53.3 N
5 mm	100%	7.24 kg / 15.96 LBS 7240.0 g / 71.0 N
10 mm	100%	7.24 kg / 15.96 LBS 7240.0 g / 71.0 N
11 mm	100%	7.24 kg / 15.96 LBS 7240.0 g / 71.0 N
12 mm	100%	7.24 kg / 15.96 LBS 7240.0 g / 71.0 N

A thin sheet is not enough to focus the entire magnetic field, which wastes potential of the holder. Should you attach a powerful product to a thin surface, the field will penetrate right through and the pull force will drop sharply. To utilize full efficiency of this neodymium's power, you need a suitably thick piece of metal. The material oversaturation causes that on thin elements (e.g., appliance housings), the holder works worse. We recommend selecting the steel dimension from these parameters.

Table 5: Thermal resistance (stability) - resistance threshold
MP 40x20x5 / N38

Ambient temp. (°C)	Power loss	Remaining pull (kg/lbs/g/N)	Status
20 °C	0.0%	7.24 kg / 15.96 LBS 7240.0 g / 71.0 N	OK
40 °C	-2.2%	7.08 kg / 15.61 LBS 7080.7 g / 69.5 N	OK
60 °C	-4.4%	6.92 kg / 15.26 LBS 6921.4 g / 67.9 N	OK
80 °C	-6.6%	6.76 kg / 14.91 LBS 6762.2 g / 66.3 N
100 °C	-28.8%	5.15 kg / 11.36 LBS 5154.9 g / 50.6 N

Ordinary NdFeB products change their properties power past the thermal threshold. Avoid high temperatures – high temperature can permanently demagnetize this product. With increasing heat, the magnet's power briefly drops. Refrain from using this product close to ovens higher than its working range. Ignoring the limit will result in permanent loss of magnetic properties.

*Technical advisory: Heat tolerance is determined by both grade, and the Permeance Coefficient Pc. Low-profile magnets (low Pc) risk losing magnetic properties at lower temperatures than taller cylinders. Warning indicator in the table indicates permanent field degradation for this specific geometry.

Table 6: Two magnets (repulsion) - forces in the system
MP 40x20x5 / N38

Gap (mm)	Attraction (kg/lbs) (N-S)	Shear Strength (kg/lbs/g/N)	Repulsion (kg/lbs) (N-N)
0 mm	179.94 kg / 396.69 LBS 5 920 Gs	26.99 kg / 59.50 LBS 26991 g / 264.8 N	N/A
1 mm	171.16 kg / 377.35 LBS 10 277 Gs	25.67 kg / 56.60 LBS 25675 g / 251.9 N	154.05 kg / 339.62 LBS ~0 Gs
2 mm	162.41 kg / 358.05 LBS 10 011 Gs	24.36 kg / 53.71 LBS 24361 g / 239.0 N	146.17 kg / 322.24 LBS ~0 Gs
3 mm	153.87 kg / 339.24 LBS 9 744 Gs	23.08 kg / 50.89 LBS 23081 g / 226.4 N	138.49 kg / 305.31 LBS ~0 Gs
5 mm	137.55 kg / 303.25 LBS 9 213 Gs	20.63 kg / 45.49 LBS 20633 g / 202.4 N	123.80 kg / 272.92 LBS ~0 Gs
10 mm	101.67 kg / 224.14 LBS 7 921 Gs	15.25 kg / 33.62 LBS 15251 g / 149.6 N	91.50 kg / 201.73 LBS ~0 Gs
20 mm	52.00 kg / 114.64 LBS 5 665 Gs	7.80 kg / 17.20 LBS 7800 g / 76.5 N	46.80 kg / 103.18 LBS ~0 Gs
50 mm	6.64 kg / 14.64 LBS 2 025 Gs	1.00 kg / 2.20 LBS 996 g / 9.8 N	5.98 kg / 13.18 LBS ~0 Gs
60 mm	3.59 kg / 7.92 LBS 1 489 Gs	0.54 kg / 1.19 LBS 539 g / 5.3 N	3.23 kg / 7.13 LBS ~0 Gs
70 mm	2.03 kg / 4.48 LBS 1 120 Gs	0.30 kg / 0.67 LBS 305 g / 3.0 N	1.83 kg / 4.03 LBS ~0 Gs
80 mm	1.20 kg / 2.64 LBS 860 Gs	0.18 kg / 0.40 LBS 180 g / 1.8 N	1.08 kg / 2.38 LBS ~0 Gs
90 mm	0.73 kg / 1.62 LBS 673 Gs	0.11 kg / 0.24 LBS 110 g / 1.1 N	0.66 kg / 1.46 LBS ~0 Gs
100 mm	0.47 kg / 1.03 LBS 536 Gs	0.07 kg / 0.15 LBS 70 g / 0.7 N	0.42 kg / 0.92 LBS ~0 Gs

Two strong neodymiums interact from a much further distance than a magnet and sheet setup. The setup of magnet-to-magnet creates a more powerful interaction and a wider radius of action. Want to build a strong closure? Use a pair of magnets instead of a neodymium and a steel. Be careful that when connecting a pair of magnets, the collision energy is extreme. The repulsion force is marginally weaker than the attraction, but still impressive.
*The magnetic induction between like poles drops to ~0 Gs at the geometric center between the magnets (due to field cancellation).
Important: Calculations show friction force of two identical neodymium magnets (friction coefficient ~0.15 for Ni-Ni coating).

Table 7: Protective zones (implants) - precautionary measures
MP 40x20x5 / N38

Object / Device	Limit (Gauss) / mT	Safe distance
Pacemaker	5 Gs (0.5 mT)	24.0 cm
Hearing aid	10 Gs (1.0 mT)	18.5 cm
Timepiece	20 Gs (2.0 mT)	14.5 cm
Mobile device	40 Gs (4.0 mT)	11.0 cm
Remote	50 Gs (5.0 mT)	10.5 cm
Payment card	400 Gs (40.0 mT)	4.5 cm
HDD hard drive	600 Gs (60.0 mT)	3.5 cm

Extremely neodym field poses a real danger to electronics as well as medical implants. These neodymiums produce a field that disrupts operation of sensitive medical devices. Be aware: the unseen radiation acts through matter and plastic. Special caution must be taken by people with cochlear implants and drug dispensers. The risk also applies to: mechanical watches, car keys, membranes, and screens. Avoid contact with magnetic cards, hard drives, or precise measuring instruments.

Table 8: Dynamics (kinetic energy) - warning
MP 40x20x5 / N38

Start from (mm)	Speed (km/h)	Energy (J)
10 mm	16.84 km/h (4.68 m/s)	0.39 J
30 mm	25.31 km/h (7.03 m/s)	0.87 J
50 mm	32.33 km/h (8.98 m/s)	1.43 J
100 mm	45.65 km/h (12.68 m/s)	2.84 J

Neodymium magnets are very brittle – a violent impact against metal causes immediate chipping. Pay attention to connection velocity – a neodymium left loose becomes dangerous. Impact energy can destroy the magnet or painful pinches to skin. Be sure to control the product during bringing near metal so it doesn't hit with great force against the steel surface. A collision at high speed means shattering of the neodymium. Wear safety glasses when working with large magnets.

Table 9: Surface protection spec
MP 40x20x5 / 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)

The following table defines the conditions under which this product can be safely used. Moisture resistance is crucial for installations in bathrooms or outdoors.

Table 10: Construction data (P_c)
MP 40x20x5 / N38

Parameter	Value	SI Unit / Description
Magnetic Flux	56 325 Mx	563.3 µWb
P_c Coefficient	0.80	High (Stable)

Total magnetic flux emitted by the pole surface. Key data when building generators and motors. The P_c coefficient defines the magnet's operating point.

Table 11: Physics of underwater searching
MP 40x20x5 / N38

Environment	Effective steel pull	Effect
Air (land)	7.24 kg	Standard
Water (riverbed)	8.29 kg (+1.05 kg buoyancy gain)	+14.5%

Rust risk: Standard nickel requires drying after every contact with moisture; lack of maintenance will lead to rust spots.

In water, the magnet feels stronger thanks to Archimedes' principle. However, remember the water resistance when pulling the rope quickly.

1. Sliding resistance

*Warning: On a vertical surface, the magnet retains only approx. 20-30% of its perpendicular strength.

2. Steel thickness impact

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

3. Thermal stability

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

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

chart generated for the permeance coefficient P_c (Permeance Coefficient) = 0.80

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 and environmental data

Chemical composition

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%

Sustainability

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: 030199-2026

Measurement Calculator

Pulling force

Force in kg

Force (N)

lbs

Field Strength

Input data into any field, and all other values change in real-time.

View more deals

Product available Ships today (order by 14:00)

UMT 29x38 white / N38 - board holder

6.81 ZŁ brutto / pcs

Product available Ships today (order by 14:00)

MW 15x2 / N38 - cylindrical magnet

1.218 ZŁ brutto / pcs

Product available Ships today (order by 14:00)

UMC 75x11/6x18 / N38 - cylindrical magnetic holder

169.86 ZŁ brutto / pcs

Product available Ships today (order by 14:00)

MP 10x4.3x4 / N38 - ring magnet

1.045 ZŁ brutto / pcs

The ring magnet with a hole MP 40x20x5 / 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 7.24 kg works great as a cabinet closure, speaker holder, or mounting element in devices.

This material behaves more like porcelain than steel, so it doesn't forgive mistakes during mounting. 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.

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 can be damaged when tightening the screw, which will become a corrosion focus. This product is dedicated for inside building use. For outdoor applications, we recommend choosing rubberized holders or additional protection with varnish.

A screw or bolt with a thread diameter smaller than 20 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 Ø40 mm (outer diameter) and height 5 mm. The pulling force of this model is an impressive 7.24 kg, which translates to 70.98 N in newtons. The product has a [NiCuNi] coating and is made of NdFeB material. Inner hole dimension: 20 mm.

These magnets are magnetized axially (through the thickness), which means one flat side is the N pole and the other is S. 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.

Pros and cons of Nd₂Fe₁₄B magnets.

Benefits

Besides their tremendous pulling force, neodymium magnets offer the following advantages:

Their power is maintained, and after approximately ten years it drops only by ~1% (theoretically),
They have excellent resistance to weakening of magnetic properties due to external magnetic sources,
By covering with a reflective coating of nickel, the element presents an proper look,
The surface of neodymium magnets generates a powerful magnetic field – this is a distinguishing feature,
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...
Thanks to flexibility in designing and the ability to customize to individual projects,
Huge importance in electronics industry – they are used in HDD drives, electric motors, medical equipment, as well as technologically advanced constructions.
Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Cons

Characteristics of disadvantages of neodymium magnets: application proposals

They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also increases its resistance to damage
When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
When exposed to humidity, magnets start to 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.
Due to limitations in creating nuts and complicated forms in magnets, we propose using casing - magnetic mechanism.
Health risk related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the context of child health protection. Additionally, small elements of these magnets can disrupt the diagnostic process medical after entering the body.
High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Holding force characteristics

Breakaway strength of the magnet in ideal conditions – what affects it?

Holding force of 7.24 kg is a measurement result conducted under the following configuration:

on a block made of structural steel, perfectly concentrating the magnetic field
possessing a thickness of minimum 10 mm to ensure full flux closure
characterized by lack of roughness
under conditions of gap-free contact (surface-to-surface)
during pulling in a direction perpendicular to the plane
at standard ambient temperature

Practical lifting capacity: influencing factors

It is worth knowing that the magnet holding may be lower subject to elements below, in order of importance:

Space between surfaces – every millimeter of distance (caused e.g. by veneer or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the nominal value.
Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of converting into lifting capacity.
Steel grade – ideal substrate is pure iron steel. Stainless steels may attract less.
Surface structure – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
Thermal environment – heating the magnet causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

Lifting capacity testing was conducted on plates with a smooth surface of optimal thickness, under perpendicular forces, however under shearing force the lifting capacity is smaller. In addition, even a minimal clearance between the magnet and the plate decreases the lifting capacity.

Safe handling of NdFeB magnets

Keep away from electronics

Navigation devices and smartphones are highly susceptible to magnetism. Close proximity with a powerful NdFeB magnet can decalibrate the internal compass in your phone.

Sensitization to coating

Allergy Notice: The Ni-Cu-Ni coating contains nickel. If redness appears, cease working with magnets and wear gloves.

Life threat

Warning for patients: Powerful magnets affect medical devices. Maintain at least 30 cm distance or ask another person to work with the magnets.

Shattering risk

Watch out for shards. Magnets can explode upon uncontrolled impact, ejecting shards into the air. Wear goggles.

Permanent damage

Standard neodymium magnets (grade N) lose power when the temperature surpasses 80°C. This process is irreversible.

Bone fractures

Large magnets can break fingers instantly. Never put your hand betwixt two attracting surfaces.

Flammability

Dust created during grinding of magnets is combustible. Do not drill into magnets unless you are an expert.

Electronic hazard

Device Safety: Strong magnets can ruin payment cards and sensitive devices (heart implants, medical aids, mechanical watches).

Respect the power

Handle with care. Neodymium magnets act from a distance and snap with massive power, often faster than you can react.

Danger to the youngest

Absolutely keep magnets out of reach of children. Ingestion danger is significant, and the effects of magnets clamping inside the body are very dangerous.

Safety First! Details about risks in the article: Magnet Safety Guide.

MP 40x20x5 / N38 - ring magnet

Product card - MP 40x20x5 / N38 - ring magnet

Magnetic properties of material N38

Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C

Physical simulation of the assembly - technical parameters

Table 1: Static force (force vs gap) - power drop MP 40x20x5 / N38

Table 2: Vertical hold (wall) MP 40x20x5 / N38

Table 3: Wall mounting (sliding) - behavior on slippery surfaces MP 40x20x5 / N38

Table 4: Steel thickness (substrate influence) - sheet metal selection MP 40x20x5 / N38

Table 5: Thermal resistance (stability) - resistance threshold MP 40x20x5 / N38

Table 6: Two magnets (repulsion) - forces in the system MP 40x20x5 / N38

Table 7: Protective zones (implants) - precautionary measures MP 40x20x5 / N38

Table 8: Dynamics (kinetic energy) - warning MP 40x20x5 / N38

Table 9: Surface protection spec MP 40x20x5 / N38

Table 10: Construction data (Pc) MP 40x20x5 / N38

Table 11: Physics of underwater searching MP 40x20x5 / N38

1. Sliding resistance

2. Steel thickness impact

3. Thermal stability

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

Chemical composition

Sustainability

Pulling force

Field Strength

View more deals

UMT 29x38 white / N38 - board holder

MW 15x2 / N38 - cylindrical magnet

UMC 75x11/6x18 / N38 - cylindrical magnetic holder

MP 10x4.3x4 / N38 - ring magnet

Pros and cons of Nd2Fe14B magnets.

Benefits

Cons

Holding force characteristics

Breakaway strength of the magnet in ideal conditions – what affects it?

Practical lifting capacity: influencing factors

Safe handling of NdFeB magnets

Keep away from electronics

Sensitization to coating

Life threat

Shattering risk

Permanent damage

Bone fractures

Flammability

Electronic hazard

Respect the power

Danger to the youngest

Physical properties of sintered neodymium magnets Nd₂Fe₁₄B at 20°C

Table 1: Static force (force vs gap) - power drop
MP 40x20x5 / N38

Table 2: Vertical hold (wall)
MP 40x20x5 / N38

Table 3: Wall mounting (sliding) - behavior on slippery surfaces
MP 40x20x5 / N38

Table 4: Steel thickness (substrate influence) - sheet metal selection
MP 40x20x5 / N38

Table 5: Thermal resistance (stability) - resistance threshold
MP 40x20x5 / N38

Table 6: Two magnets (repulsion) - forces in the system
MP 40x20x5 / N38

Table 7: Protective zones (implants) - precautionary measures
MP 40x20x5 / N38

Table 8: Dynamics (kinetic energy) - warning
MP 40x20x5 / N38

Table 9: Surface protection spec
MP 40x20x5 / N38

Table 10: Construction data (P_c)
MP 40x20x5 / N38

Table 11: Physics of underwater searching
MP 40x20x5 / N38

Pros and cons of Nd₂Fe₁₄B magnets.