Afgrow Material Data

[themaniac]

I've been using afgrow to do a fracture analysis.
When it come to the material i prefer to use the nasgro equation model but i've come across the problem that the material i'm after is not in the material database.

Anyone know a good reference (preferably a free web site- but beggers can't be choosers) for getting the variables for the nasgro equation?

Thanks people