Originally Posted by
JonathanGennick
Where I feel torquing has most value is when you have two bolts clamping the same piece of metal and want even pressure across those two bolts. Think stem bolts, faceplate bolts, and even those little Shimano crank-arm bolts. When a torque wrench isn't handy, I'll pay extra attention to the amount of hand pressure on the multiple bolts involved in, for example, a stem face plate. I try to keep the tightening pressure even across all four.
I will do without a torque wrench if one isn't handy, and will use one when it is convenient. I own three of them, so it's usually convenient unless I'm out somewhere.
I'll second this advice, stem face plates and disc rotors specifically. Adding that with stems also look at the gap left around each side. You can easily have the same torque but have the thing all sorts of crooked.
If you have no experience with this stuff a small preset torque driver for stem bolts can be very helpful. That would be something around 5nm, although they make 4.5nm, 6nm, etc. I use one set around 6nm for disc rotor bolts, helps keep rotors from warping.
Also I would lean towards very tight on a BB, not hand tight. You are not going to strip it out, That would be very hard to do. However having it come loose will very easily damage things. The tool interface will generally fail first if someone is way over tightening a bottom bracket.
Edit: When folks say they stripped the BB, they almost always mean they wrecked the splines for the tool. And you should always start a BB by hand, the only danger is cross threading it in the first couple turns. After it's threaded in smoothly by hand about half way, go to town with a big wrench/ratchet/torque wrench.