What Are the Best Magnets for 3D Printing Projects?
Small N52 disc magnets in the size your design calls for, usually metric. 6 × 2 mm discs are the standard for Gridfinity bins and snap-on lids, 6 × 3 mm or 1/4 × 1/8 Inch discs add holding power for boxes and enclosures, 8 × 2 mm and 10 × 2 mm discs suit flat panels and covers, and 3 × 1 mm or 5 × 2 mm discs fit miniatures. Use N52 for the most pull in a small pocket, epoxy-coated magnets for outdoor prints, and countersunk magnets or cylinders when a part needs a screw or a deep hole.
Our Picks by Project
| Project | Magnet | Pull force |
|---|---|---|
| Gridfinity bins and baseplates | 6 × 2 mm N52 Disc | 1.6 lb |
| Snap-on lids and small boxes | 6 × 2 mm N52 Disc or 6 × 3 mm N42 Disc | 1.6 / 2.0 lb |
| Enclosures, cases and tool holders | 1/4 × 1/8 Inch N52 Disc | 2.9 lb |
| Flat panels, covers and doors | 8 × 2 mm N52 Disc or 10 × 2 mm N52 Disc | 2.4 / 3.3 lb |
| Wall mounts and heavier parts | 12 × 3 mm N52 Disc or 1/2 × 1/8 Inch N52 Disc | 6.8 / 8.15 lb |
| Miniature bases and swappable parts | 3 × 1 mm N52 Disc or 5 × 2 mm N52 Disc | 0.3 / 1.3 lb |
| Hinges and articulated models | 3 × 3 mm N42 Cylinder | 0.6 lb |
More detail: magnets for Gridfinity and magnets for miniatures and tabletop games.
Which Shape Works Best in a 3D Print?
- Discs fit round pockets on any face and are the default for prints.
- Cylinders fit deep vertical holes and reach farther through a printed skin.
- Blocks fit rectangular pockets and long edges, such as box lids.
- Countersunk and ring magnets let you screw a printed part to a wall or frame; see Countersunk Magnets.
- Spheres make ball joints and rotating parts; see Sphere Magnets.
N52 or N42 for 3D Printing?
N52 gives the most pull in the smallest pocket, which is why most 3D printing designs specify it. N42 costs less and is plenty when you have room for a slightly thicker magnet: one step thicker in N42 often matches N52. See N42 vs. N52.
Metric or Inch Magnets?
Buy the size your model was designed for. Most printable designs, including Gridfinity, use metric magnets, and a 1/4 Inch magnet (6.35 mm) won’t fit a 6 mm pocket. If you’re designing your own part, model the pocket around the magnet you’ll actually buy. See our Metric Disc Magnets and the magnet size chart.
Thicker Magnets for Print-In Pockets
A magnet sealed inside a print has a layer of plastic between it and its partner, and that layer is an air gap. A 0.4 mm skin leaves a 6 × 2 mm N52 magnet about 45% of its pull against steel, and a 1 mm skin about 21%, by our estimates. When you seal magnets in, keep the skin thin or choose a thicker magnet.
Magnet Pairs or Magnet and Steel?
Two magnets attract each other more strongly through a printed skin than a magnet and a small piece of steel, and they self-align. A Steel Disc or washer costs less and has no polarity to get wrong. See magnet-to-magnet vs. magnet-to-steel.
Coatings and Heat
Standard nickel plating is fine for indoor prints. For outdoor or wet prints, use Epoxy Coated Magnets; see the best coating for outdoor use. Standard magnets are rated to 80 °C (176 °F), which is fine for PLA and PETG; see 3D printer heat and magnets.
Small Magnets and Children
Small magnets are a serious hazard if swallowed. Seal them fully inside printed toys and parts that children might handle.
Takeaway
For most 3D printing, start with 6 × 2 mm N52 discs, step up to 6 × 3 mm, 1/4 × 1/8 Inch or 10 × 2 mm for more hold, and match the exact size your design calls for. Use N52 for small pockets, epoxy for outdoor parts, and countersunk magnets when the print needs a screw.
- Metric Disc MagnetsSizes in Millimeters
- Disc MagnetsEvery Diameter and Thickness
- Starbond Super Glue for MagnetsFast Bond on Nickel Plating
- Magnetic Pole DetectorShows N or S Instantly
More Questions About Magnets in 3D Prints
How do I embed magnets in 3D prints?
Press or glue them into pockets, or pause the print and seal them in. See embedding magnets in 3D prints.
How much clearance should I leave for a magnet pocket?
Start with 0.1 to 0.3 mm over the magnet’s diameter. See pocket clearance.
Can the heat from a 3D printer damage neodymium magnets?
Usually not with PLA or PETG; hot beds, enclosures and annealing are the risks. See 3D printer heat and magnets.
How can I identify the poles of a magnet?
Mark one face of a stack as you separate them, or use a pole detector. See identifying magnet poles.
Which glue works best for magnets?
Super glue and two-part epoxy bond well to nickel plating. See adhesives and magnets.