Roof bar bolts

[angieoangie]

I have a 2004 Berlingo, which came with non-factory fitted roof bars
I've now removed them to save fuel and want to put the standard parallel bars back on but don't have the nuts.
Worked out they are M6, but the holes are sunk and I am also worried about tensile strength as they need to support a roof tent. Reluctant to buy generic ones. 
Any ideas where I can pick up replacements? I've tried my local Citroen dealer. 
Thanks!
Ange

[oilyrag]

I'm guessing that by sunk, it's countersunk type, but you'll find every type on Ebay. Go for High Tensile as these are probably stronger than the originals! https://www.ebay.co.uk/itm/383634364982?...BMzODx9a5g

They are available in all manner of lengths, mainly Allen socket head. Avoid stainless as it will not necessarily be strong enough and you, along with your bed, may also be 'sunk'!

Edit. Just re-read your post and you said nuts.....but maybe meant bolts/screws? !

[angieoangie]

I'm guessing that by sunk, it's countersunk type, but you'll find every type on Ebay. Go for High Tensile as these are probably stronger than the originals! https://www.ebay.co.uk/itm/383634364982?...BMzODx9a5g

They are available in all manner of lengths, mainly Allen socket head. Avoid stainless as it will not necessarily be strong enough and you, along with your bed, may also be 'sunk'!

Edit. Just re-read your post and you said nuts.....but maybe meant bolts/screws? !

Oops, yes sorry, I means screws! 
Thank you for your reply. 
Yeah, they are countersunk below the line of the bar. I'd like to be able to remove them easily as I noticed the bars have two holes each end which correspond to them being able to be re-fitted across the roof when needed - genius! The ones in the link you provided look perfect for that, too. Many thanks.

[oilyrag]

Good stuff - as High Tensile screws like these will, over time, go rusty so it might be worth coating the threads and tops with a little Vaseline to prevent them seizing, or if you have some use Copaslip.