Damascus Steel: A Beginner’s Guide
From the time of our Neanderthal ancestors to the present day, humans have always needed to defend themselves with weapons. These weapons advanced with time as we learned new things about their materials and properties.
Along the way, the craft of blacksmithing was born when we discovered the process of smelting to extract metals from rocks. Metals were easier to work with for producing harder, sharper and more powerful weapons.
Enter Wootz Steel
One of the most prized innovations in blacksmithing was wootz steel. Historical records praise the durability and sharpness of swords made from this steel. They describe in detail their beauty, with its swirly patterns that resemble waves. Now, it’s making a comeback in the form of Damascus steel.
Blacksmiths today are trying to recreate swords made out of steel with a similar composition to wootz steel. However, the task seems next to impossible as they can’t decipher the casting method employed by wootz steel blacksmiths. They use a technique called pattern welding to mimic the appearance of the original wootz steel blades.
Modern steel ingots are made using a blast furnace and come in various grades. In contrast, wootz steel ingots were originally manufactured in India using a closed crucible. By today’s standards, it would be characterized as a high carbon steel (>0.55%C) with samples found to have a carbon content ranging from 0.8% to 1.5%. Remnants of crucibles and steel fragments found in southern India date the technology to be as old as 500 BCE.
It is thought that these wootz ingots were a popular trade item and made their way to the Middle East. This is where the weapons were made using an unknown method revealing the steel's characteristic pattern and properties. It is believed that weapons made from wootz steel were popularized in the western world due to subsequent trade or conquests originating from Damascus. However, it is unclear if the weapons were truly forged here. Nevertheless, it was referred to as Damascus steel from thereon.
Modern Cast Damascus Steel
The craft for making wootz steel was thought to be lost around the mid-18th century as no artifact recovered afterward showed similar chemical composition and patterns. Efforts have been made to recreate the internal composition and external patterns of wootz steel blades.
However, results have shown very little success, as found by Verhoeven and Pendray in the 1990s. They found that the time and temperature needed to be carefully monitored, and the crucible had to melt the correct composition of metals to form carbide structures inside the ingot—attempts at forging failed to yield a blade with a regular pattern but displayed a random pattern.
Pattern Weld Steel
To get similar banded patterns, modern blacksmiths turned to a different technique called pattern welding. This method dates back to the medieval times where Celtic and Germanic swords recovered from that era showed similar patterns. This led many European blacksmiths to believe that Damascus steel weapons were made using pattern welding.
In this method, plates of steel of varying grades are stacked on top of each other and then welded together, forming a single block. It is heated in a furnace until red hot, making it soft and ready for forging. Typically, a block is alternately heated and hammered during forging to give shape to the blade, however when pattern welding, the stack-block is split from the middle and then folded onto itself, creating double the amount of layers. This is done repeatedly until the desired number of layers have been formed. The block is then given its final shape via grinding and sanding.
At this point, the metal is very brittle. It needs to be heat-treated to alter its physical properties for desired strength and ductility. This includes steps like annealing, quenching, and tempering. The blade has to be sanded again to remove the surface color, after which it can be polished. Lastly, the product is dipped in an acidic solution to remove some of the surface metal. This reveals the patterns prominently on the product due to the steel's varying grades and its chemical reaction with the acid. Blacksmiths can also create other patterns if they use bars, ball bearings, twists the metal, or split it differently during forging instead of plates.
Usually, knives are made of stainless steel, however, pattern-welded Damascus steel has found its use here. The swirls and bands are aesthetically pleasing and provide the blade with additional capabilities compared to stainless steel.
Stainless steel is a family of grades of the alloys of iron. Its composition includes a percentage of chromium and a trace amount of other metals. The quality of knives made from this class of materials greatly depends on the grade used, giving it strength and resistance.
Damascus steel knives are designed so that a combination of hard and soft grades of steel is used during the stacking process. The carbon in the metal must homogenize after forging so that it disperses uniformly throughout the blade. This allows for breaks in the metal structure, which holds the knife together, making it more rigid. Additionally, it will enable the edge to last longer as compared to stainless steel knives.
Most of the benefits of a knife made from Damascus steel only show if the blacksmith shows excellent skill and understands what to look for in the patterns that form, if any weak points emerge, or if any layers haven’t appropriately fused. This may determine the result and impact the quality and function of the knife.The most recommend type is made from layers of high-carbon steel but also has an inner core of high carbon specialty steel like VG-10 and AUS-10. This type of Damascus is more expensive of course but produces a blade of superior quality as well as one that looks very cool. It will hold its edge longer because of the hardness of the inner core but will also be very durable due to the layers of more flexible and stain resistant stainless steel. Check out Cookidea AUS-10 Damascus Chef Knife