N42 Neodymium Disc Magnets — 8 x 3 mm
Nickel-Copper-Nickel coated • Axially magnetised • Packs of 1, 10, 25, 50 and 100
1,400 g of pull — the first magnet in our range to clear a kilogram. For heavy doors, gates, structural closures and fixtures that have to hold without a mechanical catch.
Why this size
✓ Maximum pull from an 8 mm bore. 1,400 g — the strongest disc we stock at this diameter, and enough to hold a substantial door or panel closed on its own.
✓ Calculated pull: 1,400 g at direct contact. Zero gap, clean flat steel. Magnet-to-magnet also 1,400 g. Reference value, not a guaranteed working load.
✓ Here the extra height genuinely pays. 8 x 2 mm to 8 x 3 mm is a 59% gain. On our narrower discs the same step buys only around 30%, because thickness stops helping once it passes roughly half the diameter — and at 8 mm wide, 3 mm is still well inside the useful range.
✓ Works through real material. Set behind veneer, thick leather, a painted panel or a couple of millimetres of timber, a closure at this strength still feels solid rather than vague.
✓ Honest N42 grade. We state the grade we actually buy. If you see the same disc advertised as N52 at this size, treat the claim with caution.
What it is
A sintered neodymium (NdFeB) disc, 8 mm across and 3 mm thick, magnetised through its thickness — the poles are the two flat faces, not the curved edge. Two magnets meet face to face, the join sits flat, and the parts seat in the same position every time.
This is where the 8 mm range tops out, and it behaves differently from the smaller diameters. Throughout the rest of our range we advise going wider rather than taller, because holding force follows contact area and stacks up slowly with height. That advice has a threshold: roughly half the diameter. Below it, thickness still earns its keep. At 8 mm wide, a 3 mm disc is comfortably inside that zone, which is why this size gains 59% over the 8 x 2 mm rather than the 30% you would see on a 3 mm or 4 mm disc.
The result is a magnet that behaves like hardware rather than like a craft component. A cupboard door with a pair of these does not need a mechanical catch. A removable panel stays put under its own weight. It is also strong enough to demand respect in handling — see the notes below.
Specifications
| Diameter |
8 mm |
| Thickness |
3 mm |
| Weight per magnet |
1.15 g |
| Material |
Sintered neodymium iron boron (NdFeB) |
| Grade |
N42 |
| Coating |
Nickel-Copper-Nickel (NiCuNi), triple layer |
| Magnetisation |
Axial — poles on the flat faces |
| Pull to steel (calculated) |
1,400 g / 13.73 N at direct contact, zero gap |
| Magnet-to-magnet pull |
1,400 g, bare faces in direct contact |
| Shear (sideways) estimate |
Approximately 210 g — sideways load is far weaker than direct pull |
| Drill bit size |
8 mm |
| 3D print hole size |
8.1 mm |
| Maximum working temperature |
Approximately 80°C — standard for N42 |
| Country of manufacture |
China |
Pull figures are calculated reference values for a clean, flat, direct steel contact with no air gap. Paint, varnish, glue layers, fabric, card, curved surfaces and any gap at all will reduce holding force, in some cases substantially. Treat these numbers as a way to compare sizes to each other, not as a guaranteed working load.
What you get
▪ The pack size you select from the dropdown: 1, 10, 25, 50 or 100 magnets
▪ Supplied stacked pole-to-pole in a resealable bag
▪ Every magnet is the same 8 x 3 mm N42 disc — the only difference between variants is the count
What people use this size for
Woodwork, cabinetry and joinery
Heavy cabinet and wardrobe doors • full-height cupboard closures • hidden-door and bookcase catches • removable service panels and access covers • shop-fitting and furniture assemblies that come apart • jigs, fences and templates that clamp hard to a steel surface.
Workshop, garage and light engineering
Tool and fixture holders on steel benches, columns and machine frames • removable guards and covers • magnetic mounts for lamps, gauges and cameras • temporary fixings that leave no holes • sensor and switch mounts on machinery.
Display, exhibition and shop fitting
Modular stands and panel systems that break down for transport • heavy sign inserts and changeable graphics • false panels and access doors on display units • large poster and print holders.
Leatherwork, cases and heavy craft
Toolbox and instrument case closures • heavy satchels, holdalls and tool rolls • cosplay armour and prop assemblies that need to hold their own weight • presentation and flight cases.
Terrain, dioramas and large display pieces
Modular gaming tables and terrain boards • large diorama sections that lift apart • heavy resin and metal display pieces on thick plinths • cabinet and wall mounts.
Choosing between sizes
Choose 8 x 2 mm instead when: 880 g is enough — a millimetre less depth, easier to handle, and honestly the right choice for most cabinet doors, boxes and lids. This size is for when that has already proved insufficient.
Choose 6 x 3 mm instead when: an 8 mm hole is too wide for the part. 890 g from a narrower footprint, same depth.
Not the right size for miniature basing or fine craft. At 1,400 g, lifting a model straight off a steel tray will break the model long before the magnet lets go, and on card or thin board the magnet will simply tear out. Use 5 x 2 mm or 6 x 2 mm for basing, and 6 x 1 mm or 8 x 1 mm for paper craft.
Working with them
Magnet plus steel plate is usually the right answer here. A 3.2 mm recess in both halves of a joint is 6.4 mm of material, and at 1,400 g you have force to spare. Set the magnet in one side and a steel washer or plate in the other: half the drilling, half the cost, no polarity to get wrong, and still a closure that most people will describe as very strong.
Use a Forstner bit, not a twist bit. An 8 mm recess with a flat bottom is what you want in timber. A twist bit leaves a conical pit that stops the magnet seating square, and at this strength any air gap behind the magnet is force thrown away.
Epoxy, and let it fully cure. MDF, chipboard and end grain soak up PVA and leave nothing to hold. At 1,400 g a badly bedded magnet will pull straight out of its hole and take a plug of timber with it. Two-part epoxy, full cure time, then test.
Separate the stack by sliding, and do it deliberately. Pulling two of these apart takes the full 1,400 g, which is more than most people can manage cleanly with bare fingers. Push one sideways off the end of the stack instead — around 210 g, and no risk of them snapping back together across your fingertips.
Work with one at a time and clear the bench first. At this strength a loose magnet will jump several centimetres to reach steel, taking a chisel, a rule or a fingertip with it. Keep the rest of the pack closed and well away from where you are working.
Honest limitations
▪ More magnet than most jobs need. The most common mistake with this size is buying it for work an 8 x 2 mm would have done better, more cheaply and more safely. Strong is not the same as suitable.
▪ Genuinely awkward to handle. A pack of 50 or 100 is a solid bar that takes real effort to break down, and two loose ones will find each other across a workbench. This is not a magnet to tip out onto a table and sort through.
▪ It needs 8 mm of width and 3.2 mm of depth. That is 6.4 mm across both halves of a joint — more than thin stock, standard bases or most craft materials can give.
▪ Stronger than the material around it. In MDF, thin ply, soft timber or resin, the magnet is usually better anchored than its housing. When something fails it will be the material, not the magnet.
▪ Sideways load is much weaker than straight pull. Around 210 g. A door that can slide across its catch will move far more easily than one that pulls straight off.
▪ Neodymium is brittle. These are sintered, ceramic-like magnets. At 1,400 g they snap together hard enough to shatter, and fragments can leave at speed. Eye protection is sensible if you are handling a quantity of them.
▪ Indoor use. NiCuNi plating resists handling and normal indoor humidity, but it is not a marine or outdoor coating. On a gate, a shed door or in a bathroom, seal the magnet into the material rather than leaving it exposed.
▪ Heat weakens them permanently. Above roughly 80°C an N42 magnet loses strength and does not recover on cooling. Keep them away from ovens, heat guns, curing lamps and hot cars.
Important safety information
Warning — strong magnets. For adult technical, workshop and craft use. Not a toy.
Swallowing two or more magnets can cause serious internal injury. Magnets can attract to each other through the wall of the intestine, causing blockage or perforation. Seek immediate medical attention if a magnet is swallowed or inhaled. Keep away from children and pets at all times.
At this strength, magnets snapping together can trap and injure skin. Keep fingers clear of the closing faces, handle one magnet at a time, and wear eye protection when handling a quantity — neodymium is brittle and fragments can leave at speed on impact.
If you are making an item that a child may handle, the magnets must be fully enclosed and securely fixed so they cannot work loose. Loose or surface-mounted magnets are not suitable for anything intended for children.
Keep magnets away from pacemakers, implanted defibrillators and hearing aids. Keep them away from bank cards, hard drives and other magnetic media.
Store them in their bag, away from loose steel, tools and craft blades.
Dispatch
▪ Same-day dispatch on orders placed before 3 PM, Monday to Friday
▪ Sent from our own unit in Derby — we pick and pack everything ourselves
▪ Magnets are shipped within the UK only
Hobby Heaven
By Hobbyists. For Hobbyists.
We are a small family-run business in Derby, run by people who make things themselves. We publish the grade we buy and the test conditions behind every pull figure, because that is the information we wanted when we were sourcing magnets for our own projects. If something is not right, message us and we will sort it.
N42 Neodymium Disc Magnets — 8 x 3 mm
Nickel-Copper-Nickel coated • Axially magnetised • Packs of 1, 10, 25, 50 and 100
1,400 g of pull — the first magnet in our range to clear a kilogram. For heavy doors, gates, structural closures and fixtures that have to hold without a mechanical catch.
Why this size
✓ Maximum pull from an 8 mm bore. 1,400 g — the strongest disc we stock at this diameter, and enough to hold a substantial door or panel closed on its own.
✓ Calculated pull: 1,400 g at direct contact. Zero gap, clean flat steel. Magnet-to-magnet also 1,400 g. Reference value, not a guaranteed working load.
✓ Here the extra height genuinely pays. 8 x 2 mm to 8 x 3 mm is a 59% gain. On our narrower discs the same step buys only around 30%, because thickness stops helping once it passes roughly half the diameter — and at 8 mm wide, 3 mm is still well inside the useful range.
✓ Works through real material. Set behind veneer, thick leather, a painted panel or a couple of millimetres of timber, a closure at this strength still feels solid rather than vague.
✓ Honest N42 grade. We state the grade we actually buy. If you see the same disc advertised as N52 at this size, treat the claim with caution.
What it is
A sintered neodymium (NdFeB) disc, 8 mm across and 3 mm thick, magnetised through its thickness — the poles are the two flat faces, not the curved edge. Two magnets meet face to face, the join sits flat, and the parts seat in the same position every time.
This is where the 8 mm range tops out, and it behaves differently from the smaller diameters. Throughout the rest of our range we advise going wider rather than taller, because holding force follows contact area and stacks up slowly with height. That advice has a threshold: roughly half the diameter. Below it, thickness still earns its keep. At 8 mm wide, a 3 mm disc is comfortably inside that zone, which is why this size gains 59% over the 8 x 2 mm rather than the 30% you would see on a 3 mm or 4 mm disc.
The result is a magnet that behaves like hardware rather than like a craft component. A cupboard door with a pair of these does not need a mechanical catch. A removable panel stays put under its own weight. It is also strong enough to demand respect in handling — see the notes below.
Specifications
Diameter
8 mm
Thickness
3 mm
Weight per magnet
1.15 g
Material
Sintered neodymium iron boron (NdFeB)
Grade
N42
Coating
Nickel-Copper-Nickel (NiCuNi), triple layer
Magnetisation
Axial — poles on the flat faces
Pull to steel (calculated)
1,400 g / 13.73 N at direct contact, zero gap
Magnet-to-magnet pull
1,400 g, bare faces in direct contact
Shear (sideways) estimate
Approximately 210 g — sideways load is far weaker than direct pull
Drill bit size
8 mm
3D print hole size
8.1 mm
Maximum working temperature
Approximately 80°C — standard for N42
Country of manufacture
China
Pull figures are calculated reference values for a clean, flat, direct steel contact with no air gap. Paint, varnish, glue layers, fabric, card, curved surfaces and any gap at all will reduce holding force, in some cases substantially. Treat these numbers as a way to compare sizes to each other, not as a guaranteed working load.
What you get
▪ The pack size you select from the dropdown: 1, 10, 25, 50 or 100 magnets
▪ Supplied stacked pole-to-pole in a resealable bag
▪ Every magnet is the same 8 x 3 mm N42 disc — the only difference between variants is the count
What people use this size for
Woodwork, cabinetry and joinery
Heavy cabinet and wardrobe doors • full-height cupboard closures • hidden-door and bookcase catches • removable service panels and access covers • shop-fitting and furniture assemblies that come apart • jigs, fences and templates that clamp hard to a steel surface.
Workshop, garage and light engineering
Tool and fixture holders on steel benches, columns and machine frames • removable guards and covers • magnetic mounts for lamps, gauges and cameras • temporary fixings that leave no holes • sensor and switch mounts on machinery.
Display, exhibition and shop fitting
Modular stands and panel systems that break down for transport • heavy sign inserts and changeable graphics • false panels and access doors on display units • large poster and print holders.
Leatherwork, cases and heavy craft
Toolbox and instrument case closures • heavy satchels, holdalls and tool rolls • cosplay armour and prop assemblies that need to hold their own weight • presentation and flight cases.
Terrain, dioramas and large display pieces
Modular gaming tables and terrain boards • large diorama sections that lift apart • heavy resin and metal display pieces on thick plinths • cabinet and wall mounts.
Choosing between sizes
Choose 8 x 2 mm instead when: 880 g is enough — a millimetre less depth, easier to handle, and honestly the right choice for most cabinet doors, boxes and lids. This size is for when that has already proved insufficient.
Choose 6 x 3 mm instead when: an 8 mm hole is too wide for the part. 890 g from a narrower footprint, same depth.
Not the right size for miniature basing or fine craft. At 1,400 g, lifting a model straight off a steel tray will break the model long before the magnet lets go, and on card or thin board the magnet will simply tear out. Use 5 x 2 mm or 6 x 2 mm for basing, and 6 x 1 mm or 8 x 1 mm for paper craft.
Working with them
Magnet plus steel plate is usually the right answer here. A 3.2 mm recess in both halves of a joint is 6.4 mm of material, and at 1,400 g you have force to spare. Set the magnet in one side and a steel washer or plate in the other: half the drilling, half the cost, no polarity to get wrong, and still a closure that most people will describe as very strong.
Use a Forstner bit, not a twist bit. An 8 mm recess with a flat bottom is what you want in timber. A twist bit leaves a conical pit that stops the magnet seating square, and at this strength any air gap behind the magnet is force thrown away.
Epoxy, and let it fully cure. MDF, chipboard and end grain soak up PVA and leave nothing to hold. At 1,400 g a badly bedded magnet will pull straight out of its hole and take a plug of timber with it. Two-part epoxy, full cure time, then test.
Separate the stack by sliding, and do it deliberately. Pulling two of these apart takes the full 1,400 g, which is more than most people can manage cleanly with bare fingers. Push one sideways off the end of the stack instead — around 210 g, and no risk of them snapping back together across your fingertips.
Work with one at a time and clear the bench first. At this strength a loose magnet will jump several centimetres to reach steel, taking a chisel, a rule or a fingertip with it. Keep the rest of the pack closed and well away from where you are working.
Honest limitations
▪ More magnet than most jobs need. The most common mistake with this size is buying it for work an 8 x 2 mm would have done better, more cheaply and more safely. Strong is not the same as suitable.
▪ Genuinely awkward to handle. A pack of 50 or 100 is a solid bar that takes real effort to break down, and two loose ones will find each other across a workbench. This is not a magnet to tip out onto a table and sort through.
▪ It needs 8 mm of width and 3.2 mm of depth. That is 6.4 mm across both halves of a joint — more than thin stock, standard bases or most craft materials can give.
▪ Stronger than the material around it. In MDF, thin ply, soft timber or resin, the magnet is usually better anchored than its housing. When something fails it will be the material, not the magnet.
▪ Sideways load is much weaker than straight pull. Around 210 g. A door that can slide across its catch will move far more easily than one that pulls straight off.
▪ Neodymium is brittle. These are sintered, ceramic-like magnets. At 1,400 g they snap together hard enough to shatter, and fragments can leave at speed. Eye protection is sensible if you are handling a quantity of them.
▪ Indoor use. NiCuNi plating resists handling and normal indoor humidity, but it is not a marine or outdoor coating. On a gate, a shed door or in a bathroom, seal the magnet into the material rather than leaving it exposed.
▪ Heat weakens them permanently. Above roughly 80°C an N42 magnet loses strength and does not recover on cooling. Keep them away from ovens, heat guns, curing lamps and hot cars.
Important safety information
Warning — strong magnets. For adult technical, workshop and craft use. Not a toy.
Swallowing two or more magnets can cause serious internal injury. Magnets can attract to each other through the wall of the intestine, causing blockage or perforation. Seek immediate medical attention if a magnet is swallowed or inhaled. Keep away from children and pets at all times.
At this strength, magnets snapping together can trap and injure skin. Keep fingers clear of the closing faces, handle one magnet at a time, and wear eye protection when handling a quantity — neodymium is brittle and fragments can leave at speed on impact.
If you are making an item that a child may handle, the magnets must be fully enclosed and securely fixed so they cannot work loose. Loose or surface-mounted magnets are not suitable for anything intended for children.
Keep magnets away from pacemakers, implanted defibrillators and hearing aids. Keep them away from bank cards, hard drives and other magnetic media.
Store them in their bag, away from loose steel, tools and craft blades.
Dispatch
▪ Same-day dispatch on orders placed before 3 PM, Monday to Friday
▪ Sent from our own unit in Derby — we pick and pack everything ourselves
▪ Magnets are shipped within the UK only
Hobby Heaven
By Hobbyists. For Hobbyists.
We are a small family-run business in Derby, run by people who make things themselves. We publish the grade we buy and the test conditions behind every pull figure, because that is the information we wanted when we were sourcing magnets for our own projects. If something is not right, message us and we will sort it.
Specifications
-
Choose Quantity
10
-
Brand
Hobby Heaven
-
Thickness
3mm
-
Type
Disc Magnet
-
Shape
Disc
-
Item Diameter
8mm
-
Grade
N42
-
Coating
Nickel-Copper-Nickel (NiCuNi)
-
Magnetisation
Axial
-
Country of Origin
China
-
Colour
Silver
