Katana Emerald Dragon Maru Blade Suiryū Koshirae 翠龍

Clay Tempered Full Tang Shinken (真剣) | Emerald Dragon Katana: TangGu (湯谷) Maru Blade (丸造) + TangGu (湯谷) Suiryū Koshirae (翠龍拵)

This 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. The blade is clay-tempered (yaki-ire / 焼入れ) to produce a gonome hamon (互の目刃文). The koshirae includes a mokko-gata tsuba (木瓜形鍔) made of tetsu (鉄地, iron) with a blackened finish (yaki-sabi / 煮黒). The fuchi-kashira (縁頭) are made of hakudo (白銅) with engraved wave-and-dragon motifs. The habaki (鎺) is made of shakudo (赤銅), and the menuki (目貫) are made of hakudo (白銅) with sword-and-dragon engravings. The tsuka is wrapped in green synthetic fiber ito (緑色合成柄糸) over natural samegawa (鮫皮) with hishigami (菱紙) forming a diamond pattern (hishi-gumi / 菱組). The saya is finished in black sparkling lacquer (黒色閃光塗) with buffalo horn (gyūkaku / 牛角) koiguchi, kurigata, and kojiri. The sageo (下緒) is green synthetic fiber (緑色合成下緒), tightly woven.

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 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: Marudome-Hi (丸止樋), deeply engraved.
• 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
• 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): Mokko-gata Tsuba (木瓜形鍔) – Forged from tetsu (鉄地, iron) with a blackened surface (yaki-sabi / 煮黒).
• Fuchi-Kashira (縁頭): Made from hakudo (白銅, white copper), blackened and engraved with wave and dragon motifs.
• Menuki (目貫): Made from hakudo (白銅), blackened and engraved with sword-and-dragon motifs.
• Habaki (鎺): Shakudo Habaki (赤銅鎺) – Made from reddish copper alloy (shakudo / 赤銅) with a polished surface.
• Samegawa (Ray Skin 柄鮫): Natural rayskin (samegawa / 鮫皮) beneath the tsuka-maki.
• Handle Wrapping (Tsuka-maki 柄巻): Red cotton ito wrapped over hishigami (菱紙) in a diamond pattern (hishi-gumi / 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 sparkling lacquer (黒色閃光塗) with a glossy finish.

• Sageo (Cord 下緒): Green synthetic fiber sageo (緑色合成下緒), 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