Katana Golden Ripple Sanmai Blade Koran Koshirae 金漣

Clay Tempered Full Tang Shinken (真剣) | Golden Ripple Katana: TangGu (湯谷) Sanmai Blade (三枚造) + TangGu (湯谷) Koran Koshirae (琥浪拵)

This katana, named Golden Ripple, is mounted in Koran Koshirae（琥浪拵）.
The blade is forged in Sanmai（三枚構造）construction, with a hardened steel core between softer layers for strength and resilience. It is clay tempered（覆土焼入れ）, creating a flowing Gunome-midare hamon（互の目乱れ刃文）. The surface shows Masame-hada mixed with Itame-hada（柾目肌交板目肌）, combining straight and woodgrain patterns that reflect skilled folding. The saya（鞘） features brown-gold nashiji lacquer（茶金梨地塗 / Nashiji-nuri）, giving a soft amber shimmer under light. Koiguchi（鞘口）, kurigata（栗形）, and kojiri（鐺） are reinforced with water buffalo horn（牛角）. A wine-red silk sageo（赤銅色正絹下緒） is tied in traditional style. The tsuka（柄） is wrapped in brown silk ito（茶色正絹柄糸） over white samegawa（本鮫皮）, using hishigami（菱紙） to form precise diamond patterns. Fuchi-kashira（縁頭） are brass（真鍮） with nanako-ji texture（魚子地） and family crest engravings（家紋彫り）. The tsuba（鍔） is a mokko-gata brass guard（木瓜形真鍮鍔） engraved with wave motifs（波紋図）, symbolizing harmony and flow.

TangGu (湯谷) Sanmai Blade

This blade is hand-forged (Tezukuri / 手作り) using our own refined steel in Sanmai-zukuri（三枚造）construction, with a hard edge forge-welded between two softer outer layers.

Blade Forging Details

• Blade Name: TangGu Traditionally Forged Sanmai Blade (三枚造)
• Forging Method: This blade is forged in the Sanmai-zukuri（三枚造）style, with a hard steel core forge-welded between two layers of softer outer steel. It is differentially hardened using clay tempering（覆土焼入れ）, producing a hardened edge and a softer spine. This process also creates a visible hamon（刃文）
• Materials: Steel refined in-house using traditional methods（伝統的手法による自家製鋼材）
• 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 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): The blade shows masame-hada（柾目肌）with long, straight grain lines. Variations in the grain include itame-hada（板目肌）and transitional textures, created through layered forging in the sanmai-zukuri（三枚構造）style.
• Temper Line (Hamon 刃文): A Notare-style hamon（のたれ刃文）runs along the cutting edge, formed through clay tempering（覆土焼入れ / Fukutsuchi Yakiire）.

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:
  • Highest-grade shaping polish 最上・成形研磨 
  • Superior rough polish 最上・下研ぎ 
  • Detailed final polish 最上・仕上げ研ぎ 
• Key Features:
  • The blade shows Masame-hada mixed with Itame-hada（柾目肌交板目肌）, with straight grain lines and flowing woodgrain patterns. The hamon（刃文）is Gunome-midare（互の目乱れ）, formed through clay tempering（覆土焼入れ / Fukutsuchi Yakiire）. The shinogi-ji and hōmi ridge（峰）are polished.

Fittings and Mountings

Blade Fittings

• Tsuba (Handguard 鍔): Mokko-gata（木瓜形）tsuba made of brass（真鍮 / Shinchū）with engraved wave motifs（波紋図）and polished golden finish（鏡面仕上げ / Kyōmen Shiage）.
• Fuchi-Kashira (縁頭): Brass（真鍮 / Shinchū）fuchi-kashira crafted in nanako-ji style（魚子地）with engraved family crest motifs（家紋彫り / Kamon-bori）.
• Menuki (目貫): Brass menuki decorated with family crest engravings（家紋図
• Habaki (鎺): Polished brass（真鍮 / Shinchū）habaki with a smooth mirror surface
• Samegawa (Ray Skin 柄鮫): Natural white samegawa（本鮫皮 / ray skin）under the tsuka-maki.
• Handle Wrapping (Tsuka-maki 柄巻): Brown silk ito（茶色正絹) wrapped using hishigami（菱紙）to form diamond patterns.

Saya and Accessories

• Saya (Scabbard 鞘):Traditional-style saya (拵風鞘), reinforced with water buffalo horn at the koiguchi (mouth), kojiri (end), and kurigata (cord knob).
• Saya Lacquer (鞘塗): Finished in brown-gold nashiji lacquer（茶金梨地塗 / Nashiji-nuri）, creating a subtle shimmering surface that reveals fine metallic reflections under light.
• Sageo (Cord 下緒): Wine-red silk sageo（赤銅色正絹下緒）tied in traditional style.

Measurements

• Blade Weight: Approx. 0.65 kg
• Sword Weight (without Saya): Approx. 1.00 kg
• Total Weight: Approx. 1.25 kg
• Overall Length: Approx. 102 mm