Where can I find these screws for garden furniture?

[Skruvovitch]

 

[tveksamt]

For example here: https://www.clasohlson.com/se/Möbelknapp/p/11-1230

then a threaded rod that can be cut to the right length.

 

[jonaserik]

Check out IKEA, they have screws/nuts/various small spare parts for about 5 SEK per kilo, usually near the returns department here as well.
PS Make sure the threads match when you buy
http://shop.umeslap.se/Mobelknapp_stal_M6x12_Fzb?id=050-10600
https://www.specialbeslag.se/kategori/skruv-partier/mobelskruv-hylsor/