m3s nut dimensions

[Gotos]

Hi!

Thanks for this awesome project!

I'm currently building an EVA for a Cartesian printer (in case that's important: I'm building the heat insert version).
For the belt grabber, I should use an M3s nut according to the BOM and also the assembly in onShape. However, I noticed an issue - the model of the M3s nut used is 5.4 by 5.4 mm (and therefore the nut opening in the belt grabber is that size, too). But from what I can tell, DIN 562 specifies square M3 nuts to have a width and height of 5.5 mm. (I do not have access to the actual DIN 562 specs at this time, but all shops I found so far that sell nuts that they claim are up to spec list the size as 5.5 by 5.5 mm, so I'm moderately confident that this is the correct size.)

Is this a deliberate decision (e.g. for a press fit) or a mistake?