In reply to harold walmsley:
The torque figures are a bit confusing (well they aren´t really )
For our 10mm wedge bolts the recommended torque is 30 or 40Nm depending on whether it´s cracked or uncracked concrete as this type of bolt are torque controlled, that is you torque them to the given value which guarantees they will hold the rated pull-out value multiplied by whatever factor is being used, normally 4 x.
The maximum torque values given for stainless bolts are nowhere near the failure point, they are actually where the pressure on an unlubricated bolt will start to gall, for a 10mm bolt the actual failure torque is around 92Nm which one is unlikely to achieve, the better designs actually prevent this by making the small engagement ears on the clip so they shear off first and the whole bolt spins instead.
A lot depends for the extraction force on whether the threads are lubricated (stainless wedge bolts come already treated as a rule with anti-galling compound but of course you might have dropped them in the dirt), approximate values for the clamping force (the pull-out force) are 70 x torque for lubricated and 50 x for unlubricated so your 30Nm gave either 21kN or 15kN.
For 12mm bolts the diameter and the pitch are different so 56x lubricated and 42x dry, for galvanised bolts more or less in the middle of the two values.