Hi guys,

Just curious, is this what a typical stretched head bolt looks like?

Was torquing my head bolts an this one wouldn’t clamp down.




Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.

Can’t speak to “head bolt stretch”, but I just had a friend by with years of fastener experience in aircraft. His response was a heat treat problem, and that you were lucky it distorted that far before it snapped. How long since you had your torque wrench certified?

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

I haven’t had my torque wrench calibrated yet, i haven’t used it that much since new. However it is in Newton meters, so I think 75ft lbs = 101nm, it did seem bloody tight!


Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.

Some of the factory bolts are pretty weak right from the start.  If they are all from the same source, it will be wise to replace all of them.


Lawrenceville, GA