The large central hole and slot are 11mm diameter. The slot is 30mm long overall. The 4 smaller holes are 9mm. The other holes are 4mm.
So, you could use M10 in the big holes and M8 in the smaller ones.
Screwfix support: please answer these questions accurately and save everyone a bit of time.
Answered by: DaveVW
Date published: 2020-12-16