Allowable stress factors

So the steel guys got together and said, we need a more modern design, that's not as weak in some areas and too strong in other areas. Now it's the allowable stress design, and I have no idea what they're talking about when I go look at it. You have to be trained as a civil engineer. They have sections on material properties, sections on weld properties. In steel you usually can say the fatigue life or allowable stress for the base metal is typically 0.6 of the yield strength. And the weld is 0.3 of ultimate tensile strength — so they upped the safety factor for the weld by a factor of two.