The Roman armor was particularly heavy, consisting of greaves (armor for the shins) , a bronze cuirass (a breastplate to protect the upper body) and a helmet with cheek guards to protect the face. Some of the more wealthy soldiers were able to afford chain mail shirts; they added more protection although they were very heavy. it was estimated that it was over 30lb for a typical sized roman.
The legionaries wore bronze helmets with tall feathery plumes sticking out the 
top to make them look taller and more intimidating to enemies, they also included long cheek protectors and a double chin strap to ensure the helmet stayed in place during battle.
The breastplates worn by the Romans was called Lorica Segmentata. It was a type of personal armor, consisting of metal strips fashioned into circular bands, which were fastened to internal leather straps. We don't really know who used this armour, but its seen on a lot of well known monuments, such as The Arch of Constantine.
Auxilia are usually shown wearing mail cuirasses, which is a piece of armor that covers the torso, formed of one or more pieces of metal. The legionaries are depicted wearing the lorica segmentata, so we think that they were worn exclusively by legionaries and praetorians. The Lorica Segmentata was made by forging overlapping ferrous plates that were then riveted to straps made from leather; the plates were made of soft iron on the inside and rolled mild steel on the outside, this made them tough without being brittle.