Torque-to-yield fastener - Wikipedia, the free encyclopedia if ya want a headache

torque - depends on bolt design - finer the pitch -less torque need to get similar tension (think a lever - finer pitch = longer action arm)

Degrees - thermal expansion of aluminium is greater than steel. work in piping design for oil storage facility, seen 36" dia. pipe buckle 12" up when therm expan. is ignored.

there's a whole HHR load of equations & material specs involved ,ya don't want to know, take my word for it ...

the question ultimately is ... " do ya feel lucky ? "