Katana Flame Shadow Maru Blade Kōen Koshirae 焰影

Clay Tempered Full Tang Shinken (真剣) | Flame Shadow Katana: TangGu (湯谷) Maru Blade (丸造) + TangGu (湯谷) Kōen Koshirae (紅焰拵)

This katana is hand-forged (Tezukuri / 手作り) from high-carbon modern steel (高炭素現代鋼) using Maru-zukuri (丸造) construction. The blade is clay-tempered (yaki-ire / 焼入れ) to produce a straight suguha-style hamon (直刃刃文). The koshirae includes a Musashi-gata sukashi tsuba (武蔵形透鍔), forged from tetsu (鉄地, iron) with a blackened finish (yaki-sabi / 煮黒) and a double-ring sukashi (透かし) design. The fuchi-kashira (縁頭) are made from hakudo (白銅, white copper) and polished (migaki / 磨き). The habaki (鎺) is forged from shakudo (赤銅) and polished. The menuki (目貫) feature a sword-and-dragon motif (剣龍図目貫), made from hakudo (白銅), blackened and polished. The tsuka is wrapped in bright red synthetic fiber ito (赤色合成柄糸) over natural samegawa (鮫皮, ray skin) with hishigami (菱紙) forming a diamond pattern (hishi-gumi / 菱組). The saya is finished in aka-urushi (赤漆). The koiguchi (鞘口), kurigata (栗形), and kojiri (鐺) are reinforced with water buffalo horn (gyūkaku / 牛角). The bright red synthetic sageo (赤色合成下緒) completes the mounting.

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: Designed for Iaido (non-sharpened), Kenjutsu, and Tameshigiri (test cutting) practice

Blade Specifications

• Blade Length (Nagasa刃長): Approx 73 cm
• Tang Length (Nakago 茎長): Approx. 24 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)
• Hamono (Blade Pattern 刃文): Clay-tempered suguha-style (直刃) hamon – The blade is differentially hardened (yaki-ire / 焼入れ) to produce a functional temper line.

Special Features and Workmanship

Hi (Groove) Engraving

• Type: Hi-Nashi (樋なし)
• Processing Range: None (No bohi) – Solid blade for added weight and strength

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
    
• Key Features:
  • Refined blade geometry and balanced weight distribution
  • Exceptional sharpness and durability with a clean, bright-polished edge (Hashiro)
    

Fittings and Mountings

Blade Fittings

• Tsuba (Handguard 鍔): Musashi-gata Sukashi Tsuba (武蔵形透鍔) – Forged from tetsu (鉄地, iron), blackened finish (yaki-sabi / 煮黒). Double-ring sukashi (透かし) design.
• Fuchi-Kashira (縁頭): Hakudo (白銅, white copper), migaki (磨き) finish, no decorative patterns.
• Menuki (目貫): Sword-and-dragon motif (剣龍図目貫), hakudo (白銅), blackened and polished.
• Habaki (鎺): Shakudo (赤銅), polished surface.
• Samegawa (Ray Skin 柄鮫): Natural samegawa (鮫皮), under tsuka-maki.
• Handle Wrapping (Tsuka-maki 柄巻): Red silk ito (赤色正絹柄糸), wrapped with hishigami (菱紙) in hishi-gumi (菱組) pattern.

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): Aka-urushi (赤漆) with a glossy, reflective finish and subtle sparkling effect.

• Sageo (Cord 下緒): Bright red synthetic fiber sageo (赤色合成下緒), tightly woven for strength and visual harmony.

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