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UMT 29x38 white / N38 - board holder

board holder

Catalog no 230283

GTIN/EAN: 5906301814351

5.00
Diameter Ø
29 mm [±1 mm]
Height
38 mm [±1 mm]
Weight
6 g
Coating
[NiCuNi] Nickel

How we measure these parameters — certificates and measurements

see technical data »

5.54 zł net / pcs

6.81 zł with VAT (23% VAT) / pcs

price for transport

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Frequently asked questions

How many sheets of paper will one magnetic pin hold?
The category description quotes <strong>up to 20 sheets of A4</strong>, and that is the number to start from. It is not fixed: a magnet holds more firmly on a thicker base — a fridge door or a solid whiteboard backing gives more than the thin sheet behind a cheap dry-wipe board. Paper matters too: twenty sheets of office weight is not the same as twenty sheets of coated stock. For thicker stacks and folders take a larger size, 20x25 or 29x38 mm — a bigger contact area than 12x20.
Will a magnetic pin stick to any board - whiteboard, glass, cork?
No, not to every surface — a magnet only holds on a ferromagnetic material, which usually means whiteboards and glass boards that have a steel sheet underneath. Plain glass without a metal backing won't attract the magnet at all. Cork boards mostly lack a metal layer too, so the pin won't stick unless the manufacturer specifically states the board is magnetic. Before buying, a simple test helps — try any magnet against the board in the shop or at home.
Will the magnet leave a mark or scratch the board or the fridge?
No, under normal use the pin leaves no lasting mark or scratch — the bottom of the magnet has an ergonomic, smooth shape designed for contact with smooth surfaces like a lacquered fridge door or a laminated board. The risk appears only when sliding the magnet across a surface with trapped grit or other hard particles caught between the base and the board — that can cause a light scratch, the same as with any object dragged across a painted surface. Wiping the magnet's base regularly removes this risk.
What is the difference between the 12x20 and 20x25 sizes, and which one suits an office?
The main difference is holding strength and grip comfort — the UMT 20x25 has a larger magnet surface, so it holds a thicker stack of sheets more firmly and is easier to grab with your fingers. The UMT 12x20 is compact and works better where board space is tight, for example with many small notes side by side. For a typical office board holding a few sheets and schedules, both sizes work fine — the choice mainly comes down to whether holding strength or fitting more pins side by side matters more.
Are magnetic pins suitable for large-format maps and plans?
Yes, they work well for that — the larger UMT 20x25 variant is well suited to maps and plans hung on magnetic boards in offices, on construction sites, or in planning rooms, since it holds heavier, stiffer paper better than the smaller pin. For a large format, it helps to place several pins along the corners and edges of the plan rather than just one in the center — this spreads the pressure and prevents the paper from sagging under its own weight.

Guides from the knowledge base

Want to talk magnets?

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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Physical properties - UMT 29x38 white / N38 - board holder

Specification / characteristics - UMT 29x38 white / N38 - board holder

properties
properties values
Cat. no. 230283
GTIN/EAN 5906301814351
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 Ø 29 mm [±1 mm]
Height 38 mm [±1 mm]
Weight 6 g
Coating [NiCuNi] Nickel
Manufacturing Tolerance ±1 mm

Magnetic properties of material N38

Specification / characteristics UMT 29x38 white / N38 - board holder
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 and environmental data

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: 230283-2026
Measurement Calculator

Force (pull)

Field Strength

Input a value in any box, to see all other values convert in real-time.

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This shape makes operating a whiteboard convenient, fast, and does not break nails. Small size hides great power - one pin works better than a handful of regular magnets. They are aesthetic, colorful, and do not scratch the board surface thanks to a smooth base.
Despite inconspicuous size, one pin with a neodymium magnet can hold even 15-20 A4 paper sheets. They do not slide down under the weight of a single sheet like cheap advertising substitutes.
Pins are ideal for whiteboards, magnetic boards, and glass boards in offices and schools. You can use them for board games (as pawns) and educational games with children. Note: Special, even stronger neodymium magnets are needed for glass boards.
Although the magnet is tightly sealed in a plastic housing, the product is small and poses a swallowing risk. The plastic housing protects the magnet itself from breaking, increasing usage safety.
You can choose colors matching office decor, company logo, or child's preferences. Pins are made of durable plastic with vivid colors that do not fade.

Advantages and disadvantages of neodymium magnets.

Benefits

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:
  • Their magnetic field is maintained, and after around ten years it decreases only by ~1% (according to research),
  • They are extremely resistant to demagnetization induced by external field influence,
  • In other words, due to the reflective layer of silver, the element becomes visually attractive,
  • They show high magnetic induction at the operating surface, which improves attraction properties,
  • Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
  • Considering the potential of flexible molding and customization to individualized solutions, NdFeB magnets can be produced in a broad palette of shapes and sizes, which amplifies use scope,
  • Key role in future technologies – they are used in computer drives, electric motors, precision medical tools, as well as other advanced devices.
  • Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Weaknesses

Characteristics of disadvantages of neodymium magnets and ways of using them
  • Brittleness is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a steel housing, which not only protects them against impacts but also increases their durability
  • When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
  • Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
  • Due to limitations in producing threads and complex shapes in magnets, we recommend using cover - magnetic mechanism.
  • Potential hazard related to microscopic parts of magnets are risky, if swallowed, which becomes key in the context of child health protection. Furthermore, small components of these magnets can complicate diagnosis medical in case of swallowing.
  • High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Pull force analysis

Highest magnetic holding force – what contributes to it?

Magnet power was defined for the most favorable conditions, including:
  • using a sheet made of mild steel, serving as a circuit closing element
  • whose transverse dimension reaches at least 10 mm
  • with a surface perfectly flat
  • under conditions of no distance (surface-to-surface)
  • during pulling in a direction perpendicular to the mounting surface
  • at ambient temperature approx. 20 degrees Celsius

Lifting capacity in practice – influencing factors

Holding efficiency is affected by specific conditions, such as (from priority):
  • Space between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
  • Force direction – declared lifting capacity refers to detachment vertically. When attempting to slide, the magnet exhibits much less (often approx. 20-30% of maximum force).
  • Plate thickness – insufficiently thick plate does not close the flux, causing part of the flux to be escaped to the other side.
  • Material type – ideal substrate is high-permeability steel. Cast iron may generate lower lifting capacity.
  • Plate texture – smooth surfaces guarantee perfect abutment, which increases force. Uneven metal reduce efficiency.
  • Heat – NdFeB sinters have a sensitivity to temperature. When it is hot they are weaker, and at low temperatures they can be stronger (up to a certain limit).

Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under perpendicular forces, however under parallel forces the holding force is lower. In addition, even a slight gap between the magnet’s surface and the plate reduces the lifting capacity.

Safety rules for work with neodymium magnets
Electronic hazard

Powerful magnetic fields can destroy records on payment cards, hard drives, and other magnetic media. Stay away of at least 10 cm.

Compass and GPS

Be aware: rare earth magnets generate a field that interferes with precision electronics. Maintain a separation from your mobile, tablet, and GPS.

Heat sensitivity

Do not overheat. Neodymium magnets are susceptible to temperature. If you require operation above 80°C, ask us about special high-temperature series (H, SH, UH).

Do not underestimate power

Before use, check safety instructions. Uncontrolled attraction can destroy the magnet or injure your hand. Be predictive.

Metal Allergy

A percentage of the population suffer from a sensitization to nickel, which is the typical protective layer for NdFeB magnets. Extended handling may cause skin redness. We recommend wear protective gloves.

Crushing force

Risk of injury: The attraction force is so great that it can cause hematomas, pinching, and even bone fractures. Use thick gloves.

No play value

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

Machining danger

Mechanical processing of neodymium magnets carries a risk of fire hazard. Neodymium dust oxidizes rapidly with oxygen and is hard to extinguish.

Health Danger

For implant holders: Powerful magnets affect medical devices. Keep at least 30 cm distance or request help to work with the magnets.

Risk of cracking

Despite metallic appearance, the material is brittle and cannot withstand shocks. Do not hit, as the magnet may crumble into sharp, dangerous pieces.

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