Step 2) Sword making
Tanren / tempering
The iron pieces, still piled onto spatula, are then heated in the fire. The iron is repeatedly heated and pounded until the desired degree of steel is obtained. This process determines the quality of iron. pounded with the help of lye (an alkaline solution, often used for washing or cleansing), the iron becomes purer and stronger, turning to steel.
Shingane & Hi-zukuri / forming
Two separate pieces of the finished steel are fitted together to form the core and skin of the sword. Repeated pounding molds the steel into a bar which the master then shapes into a rough blade with a special shaver and fields .
Tsuchioki & Yaki-ire / shaping
A coating of clay is applied to the blade. Once dried, the clay is partly scraped off in a prescribed manner to obtain the desired intricate pattern. Each master leaves a unique pattern, which is one of two ways the sword smith imprints his signature onto the blade.
The entire blade is reheated to a certain degree. Using a heated block of grooved copper, the master corrects the curvature of the blade. A coarse stone is used to grind the blade into its final shape. The tang, <description of tang here> , is finished last. Once the tang is complete, the master inscribes his name on the blade. Some masters add unique designs or sentences.