[lendaddy]

If the idea is to get a bolt to release from thermal contraction then it's the diameter you're trying to work with not the length.


Lets take a half inch diameter bolt and assume the median thermal range (7.4 micro inches/°F).

270°F change would yield .001" reduction in diameter. A 1 " diameter bolt would be twice that and a 1/4" bolt 1/2X that.

edit:fixed the missing zero for 270°