Anyone know what diameter bolts spax shocks take? 12mm won't fit and 10mm gives loads of freeplay. 11mm might fit but can't buy any. So I guess they're non-metric. They came off fleabay have 1.9 diameter springs and came off a Westfield if this helps. Also they have M 74 stamped on the spring retainers.
Cheers.

7/16"..?

there are 2 or 3 sizes.

7/16" and 1/2"; I would need to look at the spec. sheet for the third one.

7/16" is 11 mm-ish

7/16'' must be it then, thanx guys.