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UMGW 20x15x7 [M4] GW / N38 - magnetic holder internal thread

magnetic holder internal thread

Catalog no 180316

GTIN/EAN: 5906301813729

5.00
Load capacity 9.00 kg / 88.26 N
Diameter Ø
20 mm [±1 mm]
Height
15 mm [±1 mm]
Height
7 mm [±1 mm]
Weight
15.5 g
Magnetization Direction
↑ axial
Coating
[NiCuNi] Nickel

How we measure these parameters — certificates and measurements

technical details »

5.28 zł net / pcs

6.49 zł with VAT (23% VAT) / pcs

price for transport

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price from 100 pcs
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Frequently asked questions

How much will a magnetic holder hold in practice?
The catalogue value assumes full contact with smooth steel at least 10 mm thick and a perpendicular pull. Thinner sheet, paint, rust and surface irregularities reduce it considerably: on 1 mm sheet about half remains. Lifting and vertical mounting call for an additional safety margin.
Will a holder work on stainless steel?
Not on austenitic grades 304 and 316 — they are effectively non-magnetic. It will not work on aluminium, copper or brass either. Those materials need a mechanical gripper.
Which coating for which conditions?
Nickel-copper-nickel (NiCuNi) is the standard and covers most applications. Epoxy is used for damp environments and outdoor work, zinc is sufficient for dry interiors. Holders in a steel housing or in rubber also protect the magnet against impact.

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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Technical - UMGW 20x15x7 [M4] GW / N38 - magnetic holder internal thread

Specification / characteristics - UMGW 20x15x7 [M4] GW / N38 - magnetic holder internal thread

properties
properties values
Cat. no. 180316
GTIN/EAN 5906301813729
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 20 mm [±1 mm]
Height 15 mm [±1 mm]
Height 7 mm [±1 mm]
Weight 15.5 g
Magnetization Direction ↑ axial
Load capacity ~ ? 9.00 kg / 88.26 N
Coating [NiCuNi] Nickel
Manufacturing Tolerance ±1 mm

Magnetic properties of material N38

Specification / characteristics UMGW 20x15x7 [M4] GW / N38 - magnetic holder internal thread
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%

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: 180316-2026
Magnet Unit Converter

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A magnetic holder (magnet in a steel cup) is much stronger on one side than a bare magnet of the same dimensions. Moreover, the metal housing protects the brittle neodymium magnet from cracking upon impact. The threaded hole allows creating a functional mounting point in seconds.
Care must be taken not to screw the bolt too deep into the magnet bushing. If the screw reaches the bottom of the bushing and is further tightened forcefully, it will destroy the magnet. You can use a spacer washer or lock nut to limit screwing depth.
These holders are commonly used in industry, advertising, and construction for quick mounting. They serve as a base for hooks, cable holders, organizers, and lighting systems. Ideal for fixing lighting on machine tools and welding tables.
Nominal capacity (for this model approx. 9.00 kg) is measured in ideal conditions: perpendicular detachment from thick steel (min. 10mm). On a thin surface or painted cabinet, the magnet will hold much weaker (even by 50-70%). We always recommend choosing a magnet with power reserve, especially if the surface is not ideal.
The housing has anti-corrosion protection in the form of galvanic zinc or nickel plating. For outdoor applications, we recommend additional protection with varnish or choosing a rubberized (hermetic) version. The neodymium magnet itself inside is also nickel-plated.

Strengths as well as weaknesses of Nd2Fe14B magnets.

Strengths

Besides their immense pulling force, neodymium magnets offer the following advantages:
  • They retain magnetic properties for around 10 years – the loss is just ~1% (based on simulations),
  • Magnets perfectly protect themselves against demagnetization caused by external fields,
  • A magnet with a metallic gold surface has an effective appearance,
  • Neodymium magnets generate maximum magnetic induction on a small area, which ensures high operational effectiveness,
  • Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures reaching 230°C and above...
  • Possibility of precise creating and adapting to defined applications,
  • Fundamental importance in advanced technology sectors – they are utilized in computer drives, brushless drives, diagnostic systems, as well as complex engineering applications.
  • Thanks to their power density, small magnets offer high operating force, in miniature format,

Limitations

Problematic aspects of neodymium magnets: weaknesses and usage proposals
  • They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only protects the magnet but also increases its resistance to damage
  • Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
  • They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
  • Limited possibility of producing threads in the magnet and complex shapes - preferred is cover - mounting mechanism.
  • Possible danger resulting from small fragments of magnets are risky, in case of ingestion, which gains importance in the context of child health protection. It is also worth noting that small components of these magnets can disrupt the diagnostic process medical in case of swallowing.
  • Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Holding force characteristics

Highest magnetic holding force – what affects it?

The declared magnet strength represents the maximum value, measured under laboratory conditions, namely:
  • on a plate made of mild steel, effectively closing the magnetic flux
  • possessing a massiveness of minimum 10 mm to ensure full flux closure
  • with a surface cleaned and smooth
  • without the slightest clearance between the magnet and steel
  • for force applied at a right angle (pull-off, not shear)
  • at standard ambient temperature

Key elements affecting lifting force

In real-world applications, the actual holding force results from a number of factors, ranked from the most important:
  • Distance – the presence of foreign body (paint, tape, air) acts as an insulator, which reduces capacity steeply (even by 50% at 0.5 mm).
  • Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the nominal value.
  • Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the lifting capacity (the magnet "punches through" it).
  • Material type – ideal substrate is pure iron steel. Stainless steels may attract less.
  • Plate texture – smooth surfaces ensure maximum contact, which increases field saturation. Rough surfaces weaken the grip.
  • Temperature influence – high temperature weakens pulling force. Exceeding the limit temperature can permanently damage the magnet.

Lifting capacity was determined by applying a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, in contrast under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a minimal clearance between the magnet’s surface and the plate reduces the load capacity.

Safety rules for work with neodymium magnets
Sensitization to coating

It is widely known that the nickel plating (standard magnet coating) is a strong allergen. If your skin reacts to metals, avoid direct skin contact and choose coated magnets.

Electronic devices

Very strong magnetic fields can corrupt files on payment cards, hard drives, and other magnetic media. Stay away of min. 10 cm.

Maximum temperature

Standard neodymium magnets (N-type) undergo demagnetization when the temperature surpasses 80°C. This process is irreversible.

Fragile material

Protect your eyes. Magnets can explode upon violent connection, launching sharp fragments into the air. We recommend safety glasses.

Compass and GPS

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

No play value

Only for adults. Tiny parts pose a choking risk, leading to serious injuries. Keep away from kids and pets.

Caution required

Before starting, check safety instructions. Uncontrolled attraction can destroy the magnet or injure your hand. Think ahead.

ICD Warning

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

Dust is flammable

Fire warning: Neodymium dust is explosive. Avoid machining magnets without safety gear as this risks ignition.

Serious injuries

Pinching hazard: The attraction force is so great that it can cause hematomas, crushing, and even bone fractures. Use thick gloves.

Safety First! Looking for details? Read our article: Are neodymium magnets dangerous?