Hello as a question what is the modern knowledge of the roman steel? How much was diffused , what was the level of theirblacksmiths?

http://www.amazon.com/Roman-Imperial-Armour-P...ial+armour
http://www.amazon.com/Iron-Eagles-Ind-Roman-Br/dp/0752419005

Well, the Romans definitely had steel, some of it quite good, and they used a lot of what Mike Bishop refers to as "steely iron", a low-carbon steel or high-carbon iron. Cross-sectional analysis of sword blades reveals that they sometimes put harder edges on a softer core, but some blades were basically homogenous "mild steel".

One interesting tidbit is that lorica segmentata plates are consistently harder on the outside than on the inside, apparently accomplished with hammer-hardening. And each plate is surprisingly consistent in its thickness (though the plates are not all the same), to the point where some experts are wondering if they were *rolled* rather than hammered. So there is clearly some pretty sophisticated metalwork going on!

Matthew