Torque settings are just a convenient way of consistently setting the load on a component. If you really want to be accurate you measure the extension of the bolt.
This is rather inconvenient in the field so then the next best option is the torque wrench.
But they must be used with care, the amount of torque can vary due to corrosion or dirt on the fasteners giving a false reading. Paint can do the same thing by creeping out of the joint, which is why you shouldn't paint on structural joints it acts as a lubricant.
Also you need to ensure that the bolt is the correct length. If the thing bottoms out you may have the correct torque applied but it will not apply the correct pressure to the joint which will then not function as designed.
Some large maritime fasteners came with built in indicators which were basically a loose washer under a small bolt in the head of the fastener, when the correct load was reached extension of the large bolt trapped the washer. If it came loose and you could move the washer then the bolt needed retightening.
As mentioned many engine components are preloaded so as gaskets etc compress they don't need retightening.
Also watch out for Foot pounds/foot inches or Newton metres/millimetres.
get them the wrong way round and it is a case of snap and back half a turn!
