PetroStreet

Is there any free-to-use software tool to do an initial brittle Fracture assessment of materials in service?

Straight answer, no there is no freeware which is available as per my research.
See go through UCS-66 & apply L1 of API 579, and that would be sufficient if an initial screening is what you are looking for.

Even for this particular initial screening, any spreadsheet with some materials data?

Attaching a very useful article, though could not get hold of any spreadsheet to help you through with the materials list, and their brittle fracture assessment.

Thanks novice123.
Any luck to find a database, and an evaluation tool?

Believe me, I had a sheet somewhere, which I am unable to find now.
But finding still.

And the minute later, for you irish.
I had sent email to one of my friend, and never knew that he already replied me back with this.
Enjoy!