ᐅ Ikea Billy bookshelf, assembling multiple new units together

Good morning,

I have created a wall unit using two narrow, tall Billy bookcases and one tall, wide Billy bookcase. Now I would like to screw them together to ensure everything is aligned and stable. The older models could be connected with small dowels or screws available at Ikea, but I haven’t found anything for the newer ones yet. The hole diameter is only 3.4 mm (0.13 inches), and I haven't had any luck finding suitable screws at the hardware store either. Does anyone have any advice?

Thanks in advance!

Hello.

Personally, I prefer to secure the shelves with a small additional drilled hole (which will be hidden behind books anyway) rather than risk losing the shelf pin holes. For this purpose, regular wood screws from a hardware store work perfectly.

Hello,
you are probably thinking of connector screws like

For such small holes like the ones in the Billy right now, the threaded screw would be too thin. Drill the holes out to 5mm (0.2 inches) or, as Nörgli suggested, use chipboard screws to fasten them together.