If you tighten a bolt to 60 ft lbs, does it always take 60 ft lbs to break it free? or more? Had this conversation with someone earlier. I said if you tighten a bolt into spring steel (such as a lock washer), it would take more. Also, if you have given it time for the elements to play a role (which wouldn't take that long), it could be more or less depending on temperature and moisture.

 

I would think the temperature could change that a bit.. or corrosion.. so I am going with yes it could change.

 

corrosion or rust will change the surface tension between the thread on the bolt and on the hole.



i deal with many customer's cars that shudder the torque wrench when i tighten the lug nuts instead of the smooth turn to "click".

 

When you tighten a bolt to 60 Lb. Ft., it takes more than that to loosen it. Google "stiction". Once the bolt breaks stiction, the force required to turn it drops dramatically.