Why does the temperature of materials vary so widely between AWS D1.1 and AWS 14.3. D1.1 allows you to weld when the temperature of the material is 0 degree F while 14.3 is 50 degrees F. They are both welding on ferrous and non ferrous materials some HSLA, etc... . It does not seam correct that there should be that much variation. Do you have a recommended rule to follow?