Boshi

From SwordWiki

The hamon of the kissaki is called the boshi (literally, "hat"). The tip of a blade is often said to have as rich variety of expressions as a human face. The quenching of the boshi requires considerably more skill than any other part of the process, and the quality of the boshi is a clear indicator of the skill and identifying characteristics of the swordsmith.

The kaeri is the part of hamon which extends from the tip of the boshi to the mune. There are several adjectival terms used to describe kaeri, depending on the shape- long, short, straight, irregular, and so on. The end of the kaeri is known as the tome (stop), and this is described as steep or gentle.

The boshi is also described by its shape, with the following terms.

Types of Boshi

• Choji midare komi: A choji midare hamon pattern which continues into the kissaki.

• Ichimai: A fully-tempered kissaki.

• Ichimonji kaeri: A straight , horizontal turnback. The top of the boshi is flattened off level, and the kaeri is short.

• Jizo: Jizo refers to statues of the priest Jizo, whose profile this boshi resembles. The boshi is sharply constricted about halway up and has a rounded top.

• Kaen: Flame. This boshi almost looks as if it were on fire, due to hakikake and the activity of nie.

• Ko-maru: "Small circle." This boshi runs from the yokote parallel to the cutting edge of the kissaki. The top curves around and then turns back toward the mune, describing an arc.

• Ko-maru agari: "Rising small circle." The top of the rounded part is close to the tip of the kissaki. The upper area of the boshi temper line is narrower than the lower part.
• Ko-maru sagari: "Descending small circle." The top of the ko-maru is some distance from the tip of the kissaki. The upper area of the temper line is wider than the lower part of the boshi.
• Midare komi: The irregular pattern od the hamon continues into the kissaki. The type of kaeri differs from one sword to another.

• Mishina boshi: This type of boshi is typically produced by the Mishina school. The line of the boshi runs straight from the yokote to the top. The top inclines toward a point, and the kaeri is wider.
• Nie kuzure: Abundant nie are scattered throughout the kissaki, and as a result, the boshi is not distinctly formed.

• Notare komi: Similar in shape to a portion of the notare of the hamon. The line of the boshi sags halfway down.

• O-maru: Large semi-circle. The width of the boshi is much narrower than in the ko-maru. The top sweeps around and turns back toward the mune in a large arc.

• Sansaku boshi: "Sansaku" means three swordsmiths, and this term refers to the particular boshi seen in work of Osafune Nagamitsu, Kagemitsu and Sanenaga. It is a type of ko-maru; the suguha temper line continues straight across the yokote into the boshi, the ko-maru of which starts above the yokote.
• Yakizume: Without turn-back. The boshi continues directly to the mune. There are two patterns sugu and midare komi.

Sources

• The Connoisseur's Book of Japanese Swords By Kokan Nagayama (ISBN 4-7700-2071-6)
• The Samurai Sword A Handbook By John M. Yumoto (ISBN 0-8048-0509-1)
• The Japanese Sword A Comprehensive Guide By Kanzan Sato (ISBN 0-87011-562-6)
• Swords and Hilt Weapons (ISBN 1-85375-133-2)
• Japanin Miekat By Timo Reenpää (A finnish publication no ISBN available)