10mm countersunk wall fixings - can anyone help?

[AMEdinburgh]

Does anyone know where I might source 4x 10mm countersunk wall fittings 80-100mm length. Something like the Multimonti. I am struggling to find any listing in the UK.
I have a folding seat to attach to a brick wall, through a laminated ply panel and it needs to be countersunk. The normal hex head ones, I have, interfere with the folding mechanism.

Any helpful comments greatly appreciated.

 

[Deluks]

Sfix do 100mm multi monty CS. Not 10mm though, but 4 would hold a seat. Or have you tried spax or similar frame fixings? torx drive, good to use in brickwork.

 

[AMEdinburgh]

Thank you for your interest.

I already use the 6mm 100mm C/S Multimonti but they do look a bit puny in the holes on the seat frame and probably would need some sort of bush fabricated. There is only a short vertical distance between the mounting holes and so the pull out force on the top screw could well be in excess of 6x weight on front seat edge. I would be worried about a catastophic failure and injury, hence my hope of finding a tough solution.

I might need to drill through the wall and take a bit out from the other side for a penny washer and a nut using engineering bolts but the other side is newly papered, unfortunately, hence my interest in trying to find some "one sided" fixings