Dumb question but I can't seem to find an answer...
When you see listed torque spec 'ranges' in a manual or FSM, for example (55 - 65), is this just the desirable range and you can fall anywhere in between it (equally for all bolt/nuts) if you need to salt & pepper to taste because of climate or applied anti-seize etc?
Or - Is the manual telling you to first torque all the bolts to the lower range given first then go back and hit the higher #er for final torque ?

To the best of my knowledge it's just a range, and "ideal" is probably the middle value. If there's a particular sequence or staged tightening involved, the manual text always describes it specifically.

It's just the target range. Whenever there is a pre-tensioning requirement, before the final torque setting, there is usually a bolt pattern sequence of tightening involved but both the pre-tensioning and final torque values will be specified with separate ranges. (e.g. cylinder heads, intake manifolds)

Whenever anti-seize is used, especially on small threaded connections M8 or less, it is easy to over-stretch the threads, or even break it, at the high end of the torque range because the anti-seize acts as a lubricant which will allow the bolt to be turned and tightened more until the desired torque is achieved.

Thank you, I had been opting for higher range #er on basic repairs but will try and fall shy of it by a value of 1 or 2 in the future.

In a video series I was watching (bolting back lower intake) a photo of the manual said "Divide into at least 5 steps" under final torque specs but there were only 2 torque ranges listed previously and clearly 8 bolts shown in accompanying diagram to torque ?
So it made me wonder if those 2 torque ranges were to be taken as 4 torque progressions one after the other. Compounding my confusion the mechanic read it as that as well. I guess in a mission critical situation the answer is the same because you want to sneak up on mating / compressing the surfaces evenly but I was still left wondering about the "5 steps" and what I always took to be simply a 'range'.

https://imgur.com/a/C2b3Bhk

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*(edit) - Thanks mdmellot too, I was writing the above before/as your reply posted.

fixer3 wrote: ↑

Wed Dec 20, 2023 9:20 am

So it made me wonder if those 2 torque ranges were to be taken as 4 torque progressions one after the other. Compounding my confusion the mechanic read it as that as well. I guess in a mission critical situation the answer is the same because you want to sneak up on mating / compressing the surfaces evenly but I was still left wondering about the "5 steps" and what I always took to be simply a 'range'.

Yeah. In that example, the 5 step progression only applies to the final torque range. The first step is to seat all the bolts by hand in the numbered sequence. Not hand tight necessarily, just cinched up with a wrench until they are all seated and then tighten them all in order to the 86 in-lb. The final torque is then wrenched on each bolt, one at a time in progressive steps of 4, 8, 12, 16, then 20 to 23 ft-lb.

The one thing to be careful of though is stiction force. When torqued to 16 ft-lb, it may take 20 ft-lb of torque just to overcome this frictional force to start moving the bolt again. To not be fooled by this, make the last wrenching have a higher torque progression than the previous four. (e.g. 3, 6, 9, 12, 20)

Would never have known this - thank you.