Conical Drilled Holes

[Joan_Sparky]

I assume LEGO mechanical interfacing.
It’s the only time this comes up ever, really.

Drill size of 6.5mm from overseas manufactures (LEGO)

I’m working on a new set of PCBs that use Lego studs to mount the boards. During my prototype runs I found that using non-plated holes at a size of 6.5mm worked best and gave me the most consistent fit. Plated holes were too inconsistent. My prototypes were done though OSHpark and they support drill sizes up to 265 mils (~6.731mm) for plated holes. I’m assuming they must have drill sizes up to that size and used them for the boards. A couple days ago I got a whole load of boards back from a man…