Medieval plate armor was typically around 1.5 to 5 millimeters thick, depending on the specific piece and its intended use. The thickness could vary greatly based on the region, time period, and the specific role of the armor, such as whether it was meant for battle or ceremonial purposes.
The main purpose of plate armor was to provide protection against weapons like swords, arrows, and maces. Thicker plates offered better protection but were also heavier and could restrict movement. Consequently, armorers often balanced thickness with mobility.
Armor was crafted from materials like iron and steel, and advancements over time led to improvements in both strength and weight distribution. For instance, by the late 15th century, full suits of armor were designed with articulated joints and were already quite sophisticated, allowing for enhanced mobility without sacrificing much in terms of defense.
In addition to the thickness of the plates, the way they were constructed and how they were worn also influenced their protective capabilities. For example, overlapping plates were common, allowing for better coverage and movement.