Material Composition & Differences.

ASTM A 105 is a standard specification for carbon steel forgings. It nominates a number of candidate grades suitable for use in forgings for piping applications.

It provides a very broad range of chemistries that it permits for those applications, with .35 Max Carbon being the primary determinant.

You'll have to help us out on a better nomenclature for the FE10 Low alloy steel as that designation is unfamiliar and not found in my usual (and extensive) resources.

However, That would appear tro be a grade designation, and so would not imply the various property and attribute requirements related to end use that you get with the ASTM standard.

milo