UMT 20x25 black / N38 - board holder
board holder
Catalog no 230263
GTIN/EAN: 5906301814269
Diameter Ø
20 mm [±1 mm]
Height
25 mm [±1 mm]
Weight
7 g
Coating
[NiCuNi] Nickel
3.49 ZŁ with VAT / pcs + price for transport
2.84 ZŁ net + 23% VAT / pcs
bulk discounts:
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Technical data - UMT 20x25 black / N38 - board holder
Specification / characteristics - UMT 20x25 black / N38 - board holder
| properties | values |
|---|---|
| Cat. no. | 230263 |
| GTIN/EAN | 5906301814269 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| Diameter Ø | 20 mm [±1 mm] |
| Height | 25 mm [±1 mm] |
| Weight | 7 g |
| Coating | [NiCuNi] Nickel |
| Manufacturing Tolerance | ±1 mm |
Magnetic properties of material N38
| 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 |
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 |
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Strengths and weaknesses of rare earth magnets.
Benefits
- Their power is durable, and after around ten years it decreases only by ~1% (according to research),
- They are resistant to demagnetization induced by presence of other magnetic fields,
- By using a reflective layer of gold, the element gains an elegant look,
- Neodymium magnets achieve maximum magnetic induction on a contact point, which increases force concentration,
- 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...
- Possibility of individual shaping as well as adjusting to precise needs,
- Significant place in advanced technology sectors – they are used in computer drives, drive modules, diagnostic systems, as well as complex engineering applications.
- Thanks to their power density, small magnets offer high operating force, with minimal size,
Disadvantages
- They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only shields the magnet but also increases its resistance to damage
- 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 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. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation as well as corrosion.
- Limited possibility of producing nuts in the magnet and complicated forms - preferred is a housing - magnetic holder.
- Potential hazard to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Furthermore, small elements of these devices are able to disrupt the diagnostic process medical in case of swallowing.
- Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications
Pull force analysis
Maximum holding power of the magnet – what it depends on?
- using a sheet made of high-permeability steel, functioning as a circuit closing element
- with a thickness no less than 10 mm
- with an polished touching surface
- under conditions of gap-free contact (surface-to-surface)
- for force acting at a right angle (pull-off, not shear)
- in temp. approx. 20°C
What influences lifting capacity in practice
- Distance (betwixt the magnet and the plate), since even a very small distance (e.g. 0.5 mm) can cause a decrease in force by up to 50% (this also applies to paint, corrosion or debris).
- Force direction – note that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the maximum value.
- Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
- Material composition – different alloys attracts identically. High carbon content weaken the attraction effect.
- Plate texture – ground elements ensure maximum contact, which increases force. Uneven metal weaken the grip.
- Thermal conditions – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and in frost they can be stronger (up to a certain limit).
Lifting capacity testing was carried out on a smooth plate of suitable thickness, under perpendicular forces, however under parallel forces the holding force is lower. In addition, even a slight gap between the magnet and the plate decreases the lifting capacity.
Precautions when working with neodymium magnets
Compass and GPS
Navigation devices and mobile phones are extremely susceptible to magnetism. Close proximity with a strong magnet can ruin the internal compass in your phone.
Heat sensitivity
Control the heat. Exposing the magnet to high heat will permanently weaken its properties and pulling force.
Physical harm
Protect your hands. Two large magnets will join immediately with a force of several hundred kilograms, crushing anything in their path. Be careful!
Material brittleness
Neodymium magnets are sintered ceramics, which means they are fragile like glass. Collision of two magnets leads to them breaking into shards.
Metal Allergy
Warning for allergy sufferers: The nickel-copper-nickel coating contains nickel. If an allergic reaction happens, immediately stop handling magnets and use protective gear.
Handling rules
Exercise caution. Rare earth magnets attract from a long distance and connect with massive power, often quicker than you can move away.
ICD Warning
Medical warning: Strong magnets can deactivate pacemakers and defibrillators. Stay away if you have electronic implants.
Magnetic media
Device Safety: Strong magnets can ruin payment cards and delicate electronics (heart implants, medical aids, mechanical watches).
Adults only
Product intended for adults. Tiny parts pose a choking risk, causing serious injuries. Store away from kids and pets.
Mechanical processing
Fire warning: Rare earth powder is explosive. Do not process magnets without safety gear as this risks ignition.
