I was thinking the same thing about what type bolt? towball bolts always used to be 8.8 which requires 143ft lb's and equates to 194Nm torque, sounds then to me as 218-225 is a 10.9 bolt? and for whatever reason that might be needed?!!
So what is this number? well it's a standard maximum suggest torque which was until recently based on 60% of a given size bolts true maximum, it's now been increased to 75%. Two things from that, one, it is not a rigid requirement, second, it does not then automatically follow that a little less, or indeed, a little more, would cause the joint to come loose or weaken the bolt. A single 8.8 bolt at it's max torque is applying 7 tons of clamping pressure, ditto 10.9 it's 10tons!
It is though best practice to use these recommend maximums on dry free running threads, for the same reason, by the torque wrench being used on the nut, this removes any reduction in torque applied from the friction induced by the bolt shank being tight in the hole and rubbing on the walls as it turns.
So applying all that to a pair of M16 nuts and bolts holding a towball on, little of it counts!
That's as long as your reasonably close. So put the wrench on the bolt head because there is no sensible other way and if your torque wrench only goes to 220 and assuming it's not even accurate! then that's still more than close enough.
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