SWORD BLADE TERMINOLOGY
Part I - Sword Blades

The hada is the visible design of the grain of the sword steel. It is a result of the way the sword was folded during forging. Hada can be difficult for the beginner to interpret and it is easily obscured by a poorly polished blade or one which is stained or rusted.

The hamon is the design of the tempered edge of the sword blade. It is a result of the differential cooling of the blade (quenching and tempering) after it is forged. There are numerous styles of hamon and quite commonly mixed styles such as choji-midare or midare-togari. Some of the major forms are shown below.

"Hataraki" or "activities" or "workings" in the hamon are various types of lines, streaks, dots and patches which result from the interaction of the steel during the quenching process. "Ashi" means "legs" which are streaks of nioi extending toward the ha (edge); "ko-nie" are small dots of nie above the hamon; "ji-nie" are patches of nie in the ji; "sunagashi", "kinsuji" and "inazuma" are streaks within and above the hamon; "uchinoke" are cresent shaped areas. "Chikei" are running dark lines in the ji. A proper polish is required for the activities in the hamon to be well visualized. An active hamon is normally the mark of a better quality blade. Activities are not usually seen in bar stock, oil quenched WW II era gunto blades.

        

  

Photos courtesy of Ron Polansky