Which magnet for magnet fishing? A buyer's guide
Fishing magnets for pulling metal out of rivers, lakes, canals and harbours - how to pick a model, what sellers leave out of the spec sheet, and how much the magnet actually holds in the water rather than on a test plate.
Safety first: read this before you buy
Neodymium magnets are extremely strong components and can cause injury if handled carelessly.
- Always wear work gloves and safety glasses - they protect against crush injuries and flying fragments.
- Keep magnets away from electronics: computers, phones, GPS receivers, payment cards.
- Keep at least 20 cm (about 8 in) clearance from hard drives, CRT monitors and pacemakers.
- Never let children play with magnets - swallowing and choking risk.
- Do not heat or drill a magnet. It may ignite or shatter.
- Avoid impacts. Neodymium is brittle and can break apart, throwing sharp fragments.
- If skin is pinched between magnets, cool the area with ice; for a serious injury see a doctor.
- Do not handle bare-handed if you are allergic to nickel.
- Store dry and cool, away from heat sources.
- Magnets are not corrosion-proof. After contact with water, dry the unit and protect it with technical oil.
What a fishing magnet is
Fishing magnets, also called magnetic recovery hooks or pot magnets, are tools for retrieving ferrous objects from the bottom of a body of water. Their effectiveness comes from the strong field of N38-N52 grade magnets housed in a steel cup. Unlike ferrite magnets, they hold loads of several hundred kilograms - provided the contact surface is large enough, clean, and the pull is applied in the right direction.
A first-time buyer can start with the F200 GOLD: light and compact. The more experience you gain, the larger the diameter and the higher the rated pull force you will want.
How to choose a fishing magnet
Choosing is not a matter of reading the number in the product name. Real-world performance depends on parameters many sellers never mention.
2.1 Magnet thickness, not housing height
Do not judge by the height of the steel cup. What matters is the thickness of the neodymium magnet inside it. A thin magnet set in a tall housing looks substantial and is markedly weaker - even in a good grade such as N50.
2.2 Flux density, not just the N38 or N52 label
The grade designation (N38, N42, N52) indicates potential, not the finished unit's holding force. In practice the flux density in gauss matters more. Good fishing magnets reach roughly 8,000 Gs per magnet.
A thicker N38 magnet can match a thinner N52 one - while costing less and being less prone to damage. Final strength comes from volume, thickness and build quality, not from the grade label alone.
2.3 Machined A2 stainless eyebolts, not castings
A sound fishing magnet is more than the magnet. The best eyebolts are machined from A2 stainless steel and cost around 12 zl each. Cheaper substitutes use castings of far lower strength (around 1.5 zl) which can snap the first time they catch on a heavy object.
2.4 Pull force vs shear force: the difference reaches 75%
Manufacturers quote the maximum pull force (also called breakaway force), measured with the load acting perpendicular to the contact surface. In the water you often load a side eyebolt instead, and the real holding force drops to 15-25% of the catalogue figure.
Measured example, F200 GOLD: a unit rated at 290 kg (about 640 lb) lifts roughly 38 kg (about 84 lb) in a side-loaded configuration. This behaviour is normal and applies to every fishing magnet regardless of size or grade - it is not a defect.
2.5 How we measure pull force
The procedure we use to rate our units:
- plate of S235JR structural steel, at least 10 mm (about 0.4 in) thick,
- surface clean and dry,
- magnet in axial orientation, loaded through the top eyebolt,
- reading taken with a force gauge, not a scale.
Every model in our range is measured this way, on calibrated instruments, so the result can be repeated and compared between models.
This procedure follows the pull-off test principle described in EN 13155 for lifting magnets: force is applied gradually until separation, on a plate of specified steel grade and thickness. The standard itself covers load-lifting equipment and does not apply to fishing magnets - we cite it as a reference for the method, not as a certification.
Model comparison
Prices are gross, in Polish zloty. Pull force measured under the conditions described in section 2.5. Imperial figures are rounded conversions.
| Model | Diameter | Height | Weight | Pull force | Grade | Eyebolts | Price gross |
|---|---|---|---|---|---|---|---|
| F200 GOLD | 75 mm (3.0 in) | 25 mm (1.0 in) | 900 g (2.0 lb) | 310 kg (683 lb) | N42 | 3 × M10 | 150.00 zl |
| F200 GOLD DUAL | 75 mm (3.0 in) | 25 mm (1.0 in) | 1800 g (4.0 lb) | 601 kg (1325 lb) | N42 | 3 × M10 | 245.00 zl |
| F200 PLATINIUM | 75 mm (3.0 in) | 25 mm (1.0 in) | 900 g (2.0 lb) | 365 kg (805 lb) | N52 | 3 × M10 | 270.00 zl |
| F300 GOLD (new) | 94 mm (3.7 in) | 28 mm (1.1 in) | 1600 g (3.5 lb) | 330 kg (728 lb) | N38 | 3 × M10 | 200.00 zl |
| F300 (previous) | 97 mm (3.8 in) | 40 mm (1.6 in) | 2200 g (4.9 lb) | 380 kg (838 lb) | N38 | M8 + M10 | 300.00 zl |
| F400 SILVER | 107 mm (4.2 in) | 40 mm (1.6 in) | 2350 g (5.2 lb) | 480 kg (1058 lb) | N38 | M8 + M10 | 400.00 zl |
| F550 SILVER/BLACK | 94 mm (3.7 in) | 40 mm (1.6 in) | 2262 g (5.0 lb) | 650 kg (1433 lb) | N52 | 3 × M10 | 350.00 zl |
| F600 SILVER | 135 mm (5.3 in) | 40 mm (1.6 in) | 4300 g (9.5 lb) | 680 kg (1499 lb) | N38 | M10 + M12 | 599.99 zl |
3.1 Pull force per zloty
The same range ranked by holding force against price - the best value models:
- F200 GOLD - lowest price with solid pull force, the best entry point.
- F550 SILVER/BLACK - very strong, lighter and cheaper than the F600.
- F200 GOLD DUAL - higher price, but double the force.
The F600 SILVER has the highest absolute pull force at 680 kg (about 1499 lb), but on force per zloty it loses to the F550.
Matching the model to your experience
- First time out - F200 GOLD
- Compact, light, easy to handle. Rated around 290 kg (about 640 lb). Good for learning without the risk of hooking something you cannot move.
- Stepping up - F200 PLATINIUM or DUAL
- More force in the same housing. The PLATINIUM uses an N52 magnet; the DUAL joins two F200 GOLD units into one assembly.
- Intermediate - F300 GOLD 94×28
- Larger diameter means a larger contact area and a steadier grip on big objects.
- Advanced - F400 SILVER
- More mass and deeper penetration through silt. For harder finds: scrap, tools, heavier structures.
- Professional - F550 and F600
- 650 to 680 kg (about 1433 to 1499 lb). For very heavy objects. Requires experience and rope rated to match.
Use and maintenance
Clean it after every session
- Rinse the unit in clean water.
- Remove sand, silt and rust from the magnet face and from the eyebolts.
- Dry with a towel or leave in a well-ventilated spot.
Corrosion protection
- Once dry, apply a thin film of technical oil to the magnet face.
- Do not use paint or lacquer - they damage the protective coating.
- Do not store the unit anywhere damp.
Check the bolts and eyebolts
- Check the torque on the top eyebolt and the side eyebolts regularly.
- Tighten with a wrench to the correct torque.
- Inspect the shackles - a loose one can release mid-retrieval.
Working in difficult conditions
- The magnet performs best in a vertical pull, through the top eyebolt.
- Side-loaded through an eyebolt, holding force drops by up to 75%.
- In salt water, rinse the equipment in fresh water after every session.
Accessories
Rope
The rope carries the weight of the find and gives you control over the magnet. Recommended: 8-10 mm (about 5/16 to 3/8 in) diameter, breaking strength minimum 1000 kg (about 2200 lb), polypropylene or polyester with good abrasion resistance, terminated with carabiners or shackles. A high-visibility colour is easier to spot in the water.
Work gloves
Protect against cuts, abrasion and crush injuries. Rubber, leather or reinforced fabric with a non-slip coating, sized to fit.
Safety glasses
Shield the eyes from fragments, silt and water. Polycarbonate with scratch-resistant coating and an adjustable strap.
Carry bag
Waterproof nylon or polyester, sized to the magnet. Internal compartments keep shackles and technical oil separate.
Other items
- Shackles and carabiners - for attaching the rope and releasing it quickly.
- Technical oil - corrosion protection.
- Container for finds - coins, nails, small ferrous items.
- Waterproof torch - for murky water and after dark.
Magnet fishing and the environment
Pulling scrap metal out of rivers and lakes cleans the water, reduces the hazard to fish and birds, and tidies the landscape.
- Small scrap - nails, bolts - goes to a recycling point.
- Report larger objects to the local authority or a waste disposal company.
- Report dangerous finds, ammunition included, to the police or bomb disposal.
Materials and references
Materials used
- NdFeB (neodymium-iron-boron)
- Rare-earth alloy with very high magnetic strength, the most efficient magnetic material used in fishing magnets. Requires protection against corrosion.
- NiCuNi
- Three-layer electroplated coating: nickel, copper, nickel. Protects against moisture, oxidation and mechanical damage. The industrial standard.
- A2 stainless steel
- Corrosion-resistant and non-magnetic. Used for the eyebolts. Machined rather than cast, unlike low-quality substitutes.
- S235JR steel
- Low-carbon structural steel, used as the reference plate when measuring pull force.
Links
- Neodymium magnet - Wikipedia
- Neodymium magnet production technology
- dhit.pl knowledge base
- Magnet selection calculator
Technical contact
Questions about use, maintenance or detailed material specification: bok@dhit.pl, phone +48 22 499 98 98, contact form. We prepare individual quotations for trade customers.
Edition May 2025, English HTML version September 2026. © 2005-2026 Dhit sp. z o.o.