Ok , think I've sorted it
I tightened them with a standard socket handle to what I thought would be a suitable tightness , like we did before we had torque wrenches , then checked what I had by testing it with incremental adjustments on my torque wrench . Turned out I had tightened it to about 60 Nm !
So nipped them up to 64 , job done . Glad I didn't leave them at 9 Nm , although they did feel secure !
Only thing I am left wondering is what on earth is a disc shield bolt ?