I just got an 8" M12 bolt for mine.
Well, strictly speaking, Pikey got it for me.
i asked a steel merchant the other day for 5 foot of 3"x3" box with a min wall thickness of 3mm and got a blank look i had to convert the fooker into metric........
where do yer get bolts that long then mr hand?
Paddock's part number is 336738 - look in series chassis parts. They're 90p each. Includes the nut.