`50,000-ton Wyman-Gordon forging press structural crack`

This is one where obviously the nut wasn't tight — it was peening itself apart. And another one with some really big bolts — this was a 50,000-ton forging press. There are only like half a dozen of these in the world. The posts are basically four bolts, four big bolts about a meter across. Stress concentration, there's the fatigue crack, there's the final fracture. They changed the steel and they thought they were going to a higher strength steel and everything would be wonderful. The fatigue crack is this big, there's the final fracture area. Yeah, it was higher strength, but it still broke through fracture mechanics. We won't get into the fracture mechanics right now.