I know what it's for, perhaps I should've said that. It is used to attach the door frame to the carcass. and I've already checked Screwfix with no joy Roger.
Olly, Roger, thanks, they are knock down fittings and Hafele do sell something similar but I can't find the size I'm looking for. So it looks like I will have to make something. Thanks for your help guys, I really appreciate it.