Katana Nine Syllable Maru Blade Kekkai Koshirae 九字

Clay Tempered Full Tang Shinken (真剣) | Nine Syllable Katana: TangGu (湯谷) Maru Blade (丸造) + TangGu (湯谷) Kekkai Koshirae (結界拵)

The Kuji-kiri (Nine Syllable) Katana is hand-forged (Tezukuri / 手作り) from high-carbon modern steel (高炭素現代鋼) in the Maru-zukuri (丸造) style and clay-tempered (yaki-ire / 焼入れ) to create a refined hamon that embodies precision and spiritual focus. The koshirae, named Kekkai (結界拵), features a Nine Syllable Openwork Tsuba (九字切透鐔) forged from tetsu (鉄地, iron) with a blackened finish (煮黒). The fuchi-kashira (縁頭) and menuki (目貫) are made of hakudo (白銅), blackened (煮黒), and adorned with sakura motifs (桜花文), while the habaki (鎺) is pure white copper (白銅) with a polished surface. The tsuka is wrapped in black ito (黒色柄糸) over natural samegawa (鮫皮), and the saya is finished in black ishime-ji lacquer (黒石目塗) with a textured surface, paired with a tightly woven black sageo (黒色下緒).

TangGu (湯谷) Maru Blade

This blade is hand-forged (Tezukuri / 手作り) from high-carbon modern steel (高炭素現代鋼) in a monosteel construction called Maru-zukuri (丸造).

Blade Forging Details

• Blade Name: TangGu Traditionally Forged Maru Blade (丸造)
• Forging Method: This blade is forged in the Maru-zukuri (丸造) style from a single piece of modern high-carbon steel. It is clay-tempered (yaki-ire / 焼入れ) to produce a hardened edge with a visible hamon (刃文).
• Materials: Modern high-carbon steel (kōtanso gendai-kō / 高炭素現代鋼)
• Purpose: Suitable for Kenjutsu and Tameshigiri (test cutting) practice, collection, and display. Unsharpened blades are available for Iaido upon request.

Blade Specifications

• Blade Length (Nagasa刃長): Approx 71 cm
• Tang Length (Nakago 茎長): Approx. 25 cm
• Width at Base (Motohaba 元幅): Approx. 32 mm
• Thickness at Base (Motokasane 元重): Approx. 6 mm
• Width at Tip (Sakihaba 先幅): Approx. 24 mm
• Thickness at Tip (Sakikasane先重): Approx. 4 mm
• Kissaki Length (Tip 切先長): Approx. 35 mm
• Mekugi-ana (Peg Hole 目釘穴): 1

Blade Characteristics

• Shape: Shinogi-zukuri (ridged blade 鎬造), Iori-mune (flat ridged spine 庵棟), Chū-kissaki (Medium-sized tip 中切先)
• Forging Pattern (Hada 鍛肌): None (Modern monosteel; no visible hada)
• Temper Line (Hamon 刃文): Clay-tempered gonome-style (互の目) hamon – The blade is differentially hardened (yaki-ire / 焼入れ) to produce a temper line.

Special Features and Workmanship

Hi (Groove) Engraving

• Type: Shinken Hi (真剣樋) with Marutome Tome (丸留め止め).
• Processing Range: Extends to the tip, fully polished inside the groove.

Polishing Work

• TangGu Polishing Levels:
  • High-grade shaping polish 上・成形研磨
  • High-grade rough polish 上・下研ぎ
  • High-grade final polish 上・仕上げ研磨

Fittings and Mountings

Blade Fittings

• Tsuba (Handguard 鍔): Nine Syllable Openwork Tsuba (九字切透鐔) – Forged from tetsu (鉄地, iron) with an intricate motif inspired by the Kuji-kiri ritual.
• Fuchi-Kashira (縁頭): Made from hakudo (白銅, white copper), blackened (煮黒), and engraved with sakura motifs (桜花文).
• Menuki (目貫): Crafted from hakudo (白銅), blackened (煮黒), and shaped as sakura blossoms (桜花).
• Habaki (鎺): Made from pure white copper (白銅), with a clean polished finish symbolizing purity and protection.
• Samegawa (Ray Skin 柄鮫): Natural rayskin (samegawa / 鮫皮) beneath the tsuka-maki.
• Handle Wrapping (Tsuka-maki 柄巻): Black cotton (or rayon) tsuka-ito wrapped over hishigami (菱紙) in a diamond pattern (菱組).

Saya and Accessories

• Saya (Scabbard 鞘): Traditional-style saya (拵風鞘), reinforced with water buffalo horn (牛角) at the koiguchi (鞘口), kojiri (鐺), and kurigata (栗形) for added durability.
• Saya Lacquer (鞘塗): Black ishime-ji lacquer (黒石目塗) with a textured finish.
• Sageo (Cord 下緒): Black rayon sageo (黒色木綿下緒), tightly woven.

Measurements

• Blade Weight: Approx. 0.65 kg
• Sword Weight (without Saya): Approx. 1.0 kg
• Total Weight: Approx. 1.3 kg
• Overall Length: Approx. 102 mm