The Gridfinity standard

Every dimension the generator builds to, and why each one matters. The numbers below are read straight out of the generator, so what you see here is what your file will measure.

What it is

Gridfinity is Zack Freedman's open storage system: bins on a 42 mm grid that drop into matching baseplates, so anything anybody makes to the same numbers fits in with everything else. It is free to use, and there is no authority to ask.

The community specification lives at gridfinity.xyz, and is openly a work in progress — it pins down the magnets and the labels and leaves the rest to the original videos and to what everyone has settled on in practice. Where it is silent, the figures below are the ones the printed parts in circulation actually use.

The grid

Grid pitch 42 mm Centre to centre, both axes. Everything follows from this.
Bin footprint 41.5 mm per unit 42 minus 0.5 mm of clearance — that gap is the difference between dropping a bin in and pushing it in.
Height unit 7 mm Bins come in whole units, so a 6 unit bin and two 3 unit bins finish level.
Corner radius 4 mm At the widest part of the bin.

The foot — the part that has to be right

The chamfered foot underneath every bin is what mates with a baseplate. Get this wrong and nothing else matters; get it right and your bins work with everybody's. From the bottom up:

SectionHeightShape
Lower chamfer0.8 mm45°, widening
Straight1.8 mmvertical
Upper chamfer2.15 mm45°, widening
Total4.75 mm full width at the top
0.8 1.8 2.15 one corner, drawn to scale — the printer bed below

Both chamfers are 45°, which is the steepest overhang a printer manages unsupported — that is not a coincidence, it is the reason a Gridfinity bin needs no supports.

Magnets and screws

This is the part the published specification is most definite about: the magnets are 6 mm across and 2 mm thick, the screws are M3, and there should be a hole at all four corners of every grid unit — all four, so a bin still holds however you turn it round.

Hole centres 13 mm from the middle of each unit Both axes, so four per unit.
Magnet pocket 6.5 mm × 2.4 mm A 6 mm magnet does not go into a 6 mm hole. That is the magnet plus about a quarter of a millimetre all round, which is roughly what a printer in tune leaves you.
Pressed in, no glue 6.2 mm instead 0.3 mm tighter, so the magnet stays put on friction alone. It wants a printer that is in tune — the difference between "pushes in with a thumb" and "will not go" is about a tenth of a millimetre — so it is offered rather than assumed.
Screw hole 3 mm × 6 mm deep M3 cutting its own thread in the plastic, so this is the core diameter rather than a clearance hole — a 3.2 mm hole would just spin.

Baseplates need a bottom before they can hold any of this. A plate as it comes is an open frame — the socket goes straight through, which uses less filament and lets dust fall out the bottom, and there is nowhere for a magnet to sit. Asking for magnets grows a 3.2 mm floor underneath, taking the plate to 7.95 mm. Screw holes in a plate go right through that floor, so the plate can be screwed down to the drawer with the heads sitting in the sockets.

A 6 mm screw hole is deeper than the 4.95 mm floor a plain bin has, so asking for one raises the floor to 6.8 mm and the bin holds a little less. The generator does that for you rather than drilling through into the bin, and tells you the new figure before you print.

Vase mode — two parts, on purpose

A vase-mode bin is printed as one continuous spiral of a single wall: no layer changes, no infill, no retractions, the nozzle never stops moving. That is where the time goes.

It is not the filament saving people expect. A Gridfinity bin is mostly a solid base already — the foot has to be solid to be a foot — and vase mode cannot change that, only the walls above it. Measured against the same bin printed normally:

BinNormalVase, both parts
2×1, 3 units19.7 cm³21.2 cm³ 7% more — not worth it
2×1, 6 units25.8 cm³23.2 cm³ 10% less
2×1, 12 units37.8 cm³27.3 cm³ 28% less

So: worth it for tall bins, not for short ones. Below about four units the two extra parts cost more than the thin wall saves. The time saving holds up either way, and that is usually the better reason to reach for it.

The catch is that a spiral cannot change its outline's height partway round, which is exactly what the chamfered foot needs. So the foot is a separate part, printed normally, and the two are glued together. They come as two files because a slicer's spiral vase setting applies to the whole plate — put them on the bed together and the foot comes out hollow too.

The body An open tube exactly one nozzle thick. That is why the nozzle has to be declared: the spiral draws a wall that wide whatever you model, and the base is built to fit it. Print with spiral vase on and no bottom layers — and use a brim, because a thin open outline has very little holding it to the bed.
The base The standard foot with a 1.2 mm plate over it and a 3 mm boss on top. The body drops over the boss, which is what stops a 0.4 mm wall wandering while the glue goes off. Printed normally, and it can take magnets like any other foot.
The fit 0.3 mm of slip between the boss and the body's inside, so it goes together without forcing.
Assembled The two add back up to exactly what a normal bin of that many units measures, or it would not stack with anything.

The file names say which is which — one ends -print-in-vase-mode and the other -print-normally. Getting them the wrong way round wastes a print.

Not the standard — our choices

These are not fixed by anything. They are the defaults here because they print well and use little filament; change them freely, nothing else depends on them.

  • Wall 1.2 mm and floor 1.2 mm — three passes of a 0.4 mm nozzle, which is stiff enough to drop on the floor.
  • Lid plate 1.6 mm over a standard foot, so a lid drops into a bin's stacking lip exactly as the next bin up would.
  • Label tab 12 mm deep with a 45° underside. Not in the spec, near enough universal in practice, and the reason a drawer of grey boxes is usable at all.
  • Vase-mode split at 5.95 mm — the foot plus a plate. Deep enough to be worth printing solid, shallow enough that most of the bin is still the fast part. More on that above.
  • Free size drops the foot entirely. A foot that does not line up with the grid cannot sit in a baseplate, and a part that looks Gridfinity without being it is worse than one that plainly is not.

Printing to it

  • Print one 1×1 bin and a 1×1 baseplate first and check the fit before committing to a drawerful. Every printer is a little different, and 0.5 mm is not much to play with.
  • If a bin is tight, the culprit is nearly always elephant's foot — the squash on the first layer. Most slicers have a compensation setting for it.
  • No supports, ever. If your slicer wants to add some, something is wrong.
  • Bins print fastest upside down? No — foot down, as generated. The chamfers are cut to be printable that way up.