It is my intention to continue the swordsmithing topic with the Ancient Rome sword craftsmanship.
First Roman Swords
The earliest Roman swords represented bronze cast constructions dating back to 1700 BC. The procedure of Roman sword forging evolved in two steps. Usually the first step was casting into the needed shape. Then the second one was cold working of the edges.
Bronze swords were easily sharpened and featured harder constructions than their iron counterparts. The weak point of the bronze swords was the ability to fracture where an iron sword would bend rather than break.
Iron Roman Swords
Some scientists believe that Roman iron swords appeared around 700 BC. So, the Roman sword craftsmanship developed mainly in the Republican period (510 – 27 BC). It is due to long lasting Punic Wars (First Punic War: 264 BC – 241 BC; Second Punic War: 218 BC – 202 BC), which required permanent improvement and renovation of weaponry. There are two most spread Roman iron swords:
– The Gladius (short sword) – wielded by representatives of infantry. It was normally used along with a shield.
– The Spatha (long sword) – was a cavalry weapon. It was a double-edged long sword.
The shape and the proportions of the Roman sword did not change much during this period. On the contrary, radical changes occurred in the technology of swords forging.
It is known that in Republican period the iron ore has already been mined. It was rudimentary and contained impurities of various character. Romans used to clean the ore with the help of simply water washing.
The earth provided iron chemically combined with oxygen and hydrogen, especially in the form of water. To extract water bubbles the ore was crushed into little pieces in an iron mill. Still the most harmful were oxygen impurities, they were able to cause blade crashing if some bubbles persisted after forging. To exclude oxygen content the ore was put in a furnace with charcoal. The furnace was sealed, in that way the oxygen needed for fire to burn was pulled from the ore. Thus, Romans obtained iron blocks which latter was hammered to become wonderful blades.
Today the big dilemma is – were Romans using steel or iron? At first, let’s get the point what is the difference between steel and iron.
Any metallurgist will assure you that what really distinguishes steel from iron is the amount of carbon in the metal. Wrought iron usually has a carbon content of about 0.5 %; whereas steel requires a content of carbon that equals to or exeeds 1.5 %.
The interesting thing about Romans’ swords is the fact that they unconsciously created steel! The needed carbon content was provided by the charcoal used to heat the metal. The so called carburization process created an outer layer of steel.
Steps of Roman Swordsmithing
1. Purifying the iron ore. We have already discussed the matter so we won’t stop here.
2. Heating the iron blocks in a furnace with charcoal. This technique conferred a layered construction to the blade.
3. Hammering and getting into the needed shape. The smith used a hammer to pound the metal into blade shape. He usually used tongs to hold the iron block in place. More sophisticated tools appeared later.
4. Reheating. When the blade cooled, the smith reheated it to keep it workable. While reheated and hammered repeatedly the blade become an iron confection with thin strips of steel throughout.
5. Quenching. This procedure involved the process of white heating and cooling in water. Quenching made the blade harder and stronger. At the same time it made the blade quite brittle, which was a considerable problem for the sword smiths.
6. Tempering. To avoid brittleness the blade was tempered. In another words it was reheated a final time to a very specific temperature. How the Romans do balanced the temperature? They didn’t! The smith was guided only by the blade’s color and his own experience. It should be mentioned that the Romans preferred blades that were cooled in air after being tempered to those that were quenched in water.