Kissaki Moroha Zukuri (刀尖双刃造) blades like the Kogarasu Maru are sometimes referred to as Kogarasu Zukuri (小乌王), since the blade of the Kogarasu Maru is shaped this way and is well known for its distinctive sugata. The Kogarasu Maru is unique as a bridge between the old double-edged Japanese ken (based on the Chinese jian) and the traditional Japanese tachi and eventual katana,
The Kogarasu Maru was designed with a curved double-edged blade approximately 62.8 cm long. One edge of the blade is shaped in normal tachi fashion, but unlike the tachi, the tip is symmetrical and both edges of the blade are sharp, except for about 20 cm of the trailing or concave edge nearest the hilt, which is rounded. A single koshi-hi (腰樋) style groove runs from the tang to the transition point where the blade becomes double-edged, and is invariably accompanied by a soe-hi (添樋). The hardening process yielded a straight temper line (sugaha hamon, 直刃刃文) on both sides of the blade.Items Description
Blade Sori(Curvature): 0.86 Inch / 2.2Cm
Overall Length: 40.9 Inch /104 Cm
Blade Material: high quality clay tempered t-10 carbon steel
Nagasa Length: 28.0inch / 71Cm
Blade Shape: Kogarasu Zukuri
Handle Length: 10.6Inch / 27 Cm
Blade Edge: Hand Polished Be razor sharp
Handle Material: Genuine Ray Skin + Hard Wooden
Blade Width (Near Kissaki): 0.91inch / 2.3cm
Blade Width (Near Habaki): 1.26 Inch / 3.2Cm
Kashirae Material: made of high quanlty steel
Saya Material: Hard Wooden With Lacquer Work Finished.
Kissaki Shape: Curved ken Kissaki with nice boshi
-The Blade Of The Sword Has Been Hand Forged Using The Ancient Method Of Sword Making . Full Hand Forged And Full Hand Polished.
-The blade was made of T-10 high carbon steel, and it has been laminated in a Maru configuration(Single type mono steel). differential hardened and clay tempered, oil quenched and polished be razor sharp.
-The T-10 high Carbon Steel (The steel has a 0.1% Carbon content and 0.4% Manganese.）is very solid and holds an edge well. This blade was then clay tempered and has more than 14 process hand sharpening work.
-The real hamon pattern is done in the same process as the traditional method. Harden the edge is by using the special clay wrapping the blade then put in oil to quench. It requires a lot of skills. The fire temperature can not be too high or too low it needs to be well controlled by the sword smith. The blade is then put into oil for quenching. The blade shape is done this process creates beautiful hamon hada and Martensite (grains) on the blade surface. clay to protect the edge and quenched in oil to temper the mune or spine of the sword. The hardness of the Carbon Steel measures at an impressive HRC on the Rockwell Scale. The perfect combination of the hardness of the edge steel, and the increased Sori (curvature of the blade), enables this high quality blade to easily cut through tatami straw mats or bamboo for Tameshigiri.
-This blade has a shape in "Kogarasu-maru" style, it is the nickname of one very famous sword in that style There are two Hi on each side, one is longer and shallow which is from habaki to kissaki, one is shorter and deep which is from habaki to the middle of the blade, This not only allows for a lighter blade and audible feedback when swung. but also can balance the blade to achieve optimal performance.
-Koshirae: The Tsuba (Guard), Fuchi (Sleeve) And Kashira (Buttcap) Of The Sword Made Of High Quality steel Shaped. The brass Habaki (Blade Collar) Is A One Piece Construction. Two Seppas (Spacer) Secure The Tsuba.
-Tsuka: The Tsuka (Handle) Core Is Wooden And It Is Tightly Wrapped Over Genuine Ray Skin (Samegawa) With suede leather Ito Wrapped. The Full Tang Of The Sword Is Secured By Two Mekugi (Peg) . You Can Unassembled The Blade From The Handle By Taking Out 2 Pegs. Two black dragon Menuki (Ornament) Are On Each Side Of The Tsuka.
-Saya: The Saya (Sheath) Made Of Real Hardwooden Finished High Quality Japanese Lacquer Work Be Shine. A High Quality Silk Sage-O Has Been Tied Around The Kurigata (Knob) Of The Sheath. The Koiguchi has been hardened.