Quote Originally Posted by Urnamma
Segmentata has only a short use chronology, and is also restricted to a rather small part of the Roman army from what we can tell. It was, in all estimation, a rather bad form of protection. Easily susceptible to missile fire, blunt force trauma, etc, and is notoriously difficult to fabricate (you can't just order sheet metal in the ancient world).

ehm....as far as i have read, your are only partially right.

a.
Certainly segmentata is not the best from protection. It´s protects only from hips upwards, certainly is not as flexible as mail and needs much more care to prevent from rusting.

b.
The protection from different weapons is debatable, given the fact that a roman soldier, especially a legionary, should have been hit by an enemies weapon rarely IF he can fight in his own manner => Shield covering from knee upwards to the chin.

c.
But i would disagree that it is used by a "rather small" part of the roman army.
Right, the mail armour was used in much larger amount than Segmentata.
But this takes into account that Auxiliaries only wears mail.
Leaving that fact out, i would suggest that at least 50% of the legionary infantry wore Segmentata.
This type of armour came into "regular" use in first half of 1st century AD and was in use at around 250AD...so ca. 200 years of use.

d.
As far as i´m informed, the Segmentata was introduced JUST BECAUSE it was pretty easy and fast to fabricate, though it perhaps wasn´t cheaper than mail.
You are right that sheet metal was uncommon in ancient time, because it has to be hammered (rolling was unknown).
but iron sheet metal was easier to hammer (if you know the right procedure) than cutting 30.000-40.000 iron/bronze rings. Assembly of the rings takes a lot of time also.
Some authors speak of 180h for the completion of a simple, short auxiliary mail shirt. Completing of a segmentata armour takes only around 60h.
additionally authors assume that a ancient segmentata weighs 4,5kg compared to 5,5kg+ for simple mail shirts.
the time factor outranks every other difficulty, as the increasing losses in battle had to be replaced in short time.

so all in all Segmentata armour was certainly lighter in weight, easier and faster to produce but might have less protection and needs more care from the soldier.
it makes it easier for the roman state to field the heavy infantry with an adequate level of protection and equipment.