Pattern Welding

Pattern welding is the practice in sword and knife making of forming a blade of several metal pieces of differing composition that are forge-welded together and twisted and manipulated to form a pattern. Often incorrectly called Damascus steel (which is produced by a different process), blades forged in this manner often display bands of slightly different coloration along their entire length. These bands can be brought out for cosmetic purposes by proper polishing or acid etching. Originally, pattern welding was used to combine steels of different carbon contents (generally wrought iron and cast iron), providing the desired mix of hardness and toughness needed for highly demanding tasks such as cutting through armor. Although modern steelmaking processes negate the need to blend different steels, pattern welded steel is still used by custom knifemakers for the cosmetic effects it produces.