Thanks.bjde0b wrote: BTW I liked the detailed explaination.
Here is a little proof in the pudding so to speak.bjde0b wrote:The bolt was hot when snapped so the yield strength was reduced.
It was not that the whole bolt was too hot. It was the steel around one of the tiny internal flaws that heated and lowered that areas yield strength. Those over heated steel molecules let go of each other and started a tear that went across the entire bolt. If you look at a snapped bolt, you can spot the starting point of the tear and tell where the flaw is. There is a peak or point on the surface of the separation. This is where the steel was softened and stretched to a point as the rest of the steel around it tore apart.
Lee