Manufacture
By the time of the Roman Republic, which flourished during the Iron Age, the classical world was well-acquainted with steel and the steel-making process. Pure iron is relatively soft, but pure iron is never found in nature. Natural iron ore contains various impurities in solid solution, which harden the reduced metal by producing irregular-shaped metallic crystals. The Gladius is generally made out of steel.
The Chalybes of the Caucasus region were metallurgists for Iron-Age Europe and they had found that increasing carbon content produced harder steel. In Roman times ore was reduced in a bloomery furnace, as the blast furnace had not yet been invented, at least in western society. The temperature did not become high enough to actually melt the metal. The resulting pieces were called blooms, which were further worked to remove slag inclusions from its porous surface.
A recent metallurgical study of two Etruria swords, one in the form of a Greek kopis from 7th century BC Vetulonia, and one in the form of a gladius Hispaniensis from 4th century BC Chiusa, gives some insight concerning the manufacture of Roman swords. The Chiusa sword comes from Romanized Etruria; thus, regardless of the names of the forms (which the authors do not identify), the authors believe the process was continuous from the Etruscans to the Romans.
The Vetulonian sword was crafted by the pattern welding process from five blooms reduced at a temperature of 1163 °C. Five strips of varying carbon content were created. A central core of the sword contained the highest: 0.15–0.25% carbon. On its edges were placed four strips of low-carbon steel, 0.05–0.07%, and the whole thing was welded together by forging on the pattern of hammer blows. A blow increased the temperature sufficiently to produce a friction weld at that spot. Forging continued until the steel was cold, producing some central annealing. The sword was 58 cm (22.8 in) long.
The Chiusian sword was created from a single bloom by forging from a temperature of 1237 °C. The carbon content increased from 0.05–0.08% at the back side of the sword to 0.35–0.4% on the blade, from which the authors deduce some form of carburization may have been used. The sword was 40 cm (15.7 in) long and was characterized by a wasp-waist close to the hilt.
Roman swords continued to be forged both as composites and from single pieces. Inclusions of sand and rust weakened the two swords of the study and no doubt limited the strength of swords during the Roman period.
Read more about this topic: Gladius
Famous quotes containing the word manufacture:
“The great cry that rises from all our manufacturing cities, louder than the furnace blast, is all in very deed for this—that we manufacture everything there except men.”
—John Ruskin (1819–1900)
“I believe that the miseries consequent on the manufacture and sale of intoxicating liquors are so great as imperiously to command the attention of all dedicated lives; and that while the abolition of American slavery was numerically first, the abolition of the liquor traffic is not morally second.”
—Elizabeth Stuart Phelps (1844–1911)
“The profession of magician, is one of the most perilous and arduous specialisations of the imagination. On the one hand there is the hostility of God and the police to be guarded against; on the other it is as difficult as music, as deep as poetry, as ingenious as stage-craft, as nervous as the manufacture of high explosives, and as delicate as the trade in narcotics.”
—William Bolitho (1890–1930)