Why were overlapping bronze scales easier to make than a full metal helmet?

Overlapping bronze scales were significantly easier to produce than a full metal helmet because they involved creating small, individual metal plates that could be perforated and attached to a protective garment. In contrast, forging an integral, one-piece dome of metal capable of covering the entire head was one of the most demanding challenges for an armourer.12

While scale armour required only the production of small, manageable components, crafting a helmet—such as the Corinthian Greek helmet—required the careful, graduated forging of a single piece of bronze to achieve the necessary shape and thickness. Because of these technical demands, even the simplest helmet represented a far greater manufacturing hurdle than the assembly of scale armour.21