When I was still working at a nuke power plant, we had training on the importance of torque to spec.
When the proper torque is applied with a Never Seize type lubrication on the threads and on the nut or bolt face, it actually stretches the bolt a given amount.
Lube is really important to get the right torque for the stretch, A dry rusty bolt will hit the torque spec without the proper stretch.
On the reactor cooling pumps seals housing, we used a hydraulic tool that screwed on the stud threads above the finger tight lubed nut and stretched the studs. Pumped it up to some high-pressure stat the procedure listed and then turn the nut to finger tight again, release the hydraulic pressure and then move on to the next studs listed in the bolting sequence. These were on 3 inch studs and Phak1 probably had the same training.
Here a video of a set being used on some small studs.
www.youtube.com/watch?v=yinyrZCvywIDon
