Damascus steel is a steel used in Middle Eastern swordmaking from about 1100 to 1700 AD. Damascus swords were of legendary sharpness and strength, and were apocryphally claimed to be able to cut through more "ordinary" European swords and even rock. The technique for making Damascus steel remains a mystery even with the presences of numerous well-preserved examples. Recent research into the structure and composition of the steel by a Dresden scientist claims that the strength of the steel was a result of carbon nanotubes and carbide nanowires present in the structure of the forged metal.
Damascus swords often had an obvious patterned texture on their surface. Several other steelmaking techniques also result in patterned surfaces, and have often been sold as Damascus steel, Damascened steel and sometimes watered steel. The most common technique for producing these materials is the pattern welding, which is today widely used for custom knife making. Skilled swordsmiths can manipulate the patterns to mimic the complex designs found in the surface of the original, medieval Damascus steel.