ABOUT DAMASCUS STEEL
What is Damascus steel and how were barrels made?
Damascus steel is iron and steel intertwined.
Barrel makers hammer-forged together alternating strips of low carbon iron, which was malleable but weak, and high carbon steel, which was strong but brittle. These laminated steel bars were rolled into rods, the rods twisted and welded together into ribbons, and the ribbons coiled around a mandrel.
What causes the pattern?
In the visible pattern of a Damascus steel barrel, we see the structure of the intertwined layers of high-carbon steel and low-carbon iron.
- The visible pattern emerges as the bluing (or browning) and etching agents attack the high carbon steel and low carbon iron differently.
Pictured below is a set of barrels in which the left barrel shows how Damascus steel looks before the refinishing process and the right barrel after refinishing.
What causes differences in shade and contrast?
Carbon content of the steel.
For blued Damascus barrels, the different layers will appear in shades from silver (iron) to black (steel).
For browned Damascus barrels, the layers will appear either in shades from silver to brown or from shades of light brown to dark brown depending on the finishing process.
Quality is largely determined the ratio of steel to iron, the number of layers of layers of iron and steel forged into a bar or rod, and the number of rods forged into the ribbon of metal that was wrapped around a mandrel to become the barrel.
In general, higher quality barrels tend to have a higher percentage of steel and a higher number of rods in the ribbon.
In general, higher quality barrels tend to have thinner layers of iron and steel in a rod, lower quality thicker.
Although there was no industry-wide criteria to define different quality levels when barrels were made, today two-rod Damascus-steel barrels are considered to be standard Damascus. Three-rod barrels are often categorized as fine-Damascus, four-rod as very-fine or extra-fine Damascus, and five to six-rod as finest Damascus.
Contrast between layers in the pattern also offers clues. When thin layers of iron and steel were forged together under intense heat into a rod, some carbon molecules from the steel were transferred to the iron. This result in less differentiation in color in higher quality barrels (i.e., shades of grey rather than black and white) when finished through a process of bluing and etching.
Sherman Bell & Tom Armbrust, “Finding Out for Myself – Part IX: Fluid Steel, Stronger than Damascus?” Double Gun Journal (Summer, 2005), pp. 29-34.
Sherman Bell, “Finding Out for Myself – Part XIII: Wall Hanger Rendezvous – Special Tests,” Double Gun Journal (Spring, 2007), pp. 20-29.
Sherman Bell, “Finding Out for Myself – Part XIV: Wall-Hanger Rendezvous – A Different Twist,” Double Gun Journal (Summer, 2008), pp. 18-29.
Charles Fergus, “Iron & Steel Intertwined: Unraveling the mysteries of Damascus Barrels,” Shooting Sportsman (May/June 1999), pp. 44-47, 92-94.
Oscar L. Gaddy, “The Finishing of Damascus Steel,” Double Gun Journal (Autumn 1997), pp. 167-172.
Drew Hause, “Damascus Mythology & Reality: An Effort to Correct the Misinformation Found in Sporting Literature,” Double Gun Journal (Summer, 2016), pp. 97-107.
“The History, Art, and Science of Pattern Welded Shotgun Barrels,” http://DamascusKnowledge.com
“The Making of Damascus Barrels: A 1925 Documentary Film,”