A new doctoral thesis by Dr. Panagiota Manti on the construction of Greek bronze helmets is now available online (here). Manti had an unusual theory, namely that some Greek helmets were cast in something close to their final form then reshaped by hammering. This idea goes against a lot of comparative evidence for armour being hammered from sheets and bars, and casting something as large, thin, and complex as a Corinthian helmet would be difficult. Rather than simply speculate, or try to cast a helmet, Manti took the trouble to find tests which were capable of distinguishing between her theory and the leading alternative, carried out these tests, and published the results. This approach is more difficult, but it can also provide much stronger evidence for a theory. Manti believes that she has found evidence that yes, many Corinthian helmets were cast roughly to shape then hammered for strength and delicate forming. She also believes that only one helmet in her sample was tinned, a style of decoration known from Roman and medieval copper-alloy objects.
While I do not have time to read Manti’s whole thesis, and lack the training in metallurgy to assess its argument, I hope that some of my readers will find it helpful.