2.5 N/A crankshaft pulley bolt

Hi all, just wondering really what size socket is needed for the crankshaft pulley bolt on a 2.5 N/A diesel? I've done a search and couldn't find anything. I know I could just measure it AF but if one you know the size it would be very helpful. From what I have searched its a size between 40m mand 43 but I couldn't find anything definitive and don't particularly want to order a socket of each size. Call it being lazy if you will but it would be handy to know the right size

We got it off using a box spanner which is very mis shapen know and a couple of adjustables along with a lump hammer, far from ideal.

41mm fits mine.

Thanks very much A socket shall be ordered soon as

mine is 41mm aswell