|I tensile tested two stock VG30DETT head bolts today to see just how strong they are. They came up at 186ksi with a yield of ~165ksi.
As you can see below, they both broke in the same place in roughly the same manner. The point of fracture is due to the threads reducing the cross-section at the root of the thread. I was hoping they would break somewhere in the middle of the shank for a good elongation and reduction of area measurement, but so be it.
FYI - this does not mean they are junk, it's just a measuremnt in which someone can use to compare to other alternatives out there, that is all it is good for.