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Whale-shaped Japanese utility knife by Toru Yamashita
  • Whale-shaped Japanese utility knife by Toru Yamashita
  • Close up of the tail on the whale-shaped knife by Toru Yamashita.
  • Close up of the hammering and colors on the Kogatana-style, Toru whale Japanese utility knife
  • Whale-shaped Japanese utility knives made with SK5 steel. SK5 is a common Japanese tool steel.
  • Makko and Mink styled whale-shaped Japanese utility knives by Yamashita, Toru.
  • Makko and Mink styled whale-shaped utility knives on a stone surface.
  • Whale-shaped Japanese utility knife by Toru Yamashita
  • Close up of the tail on the whale-shaped knife by Toru Yamashita.
  • Close up of the hammering and colors on the Kogatana-style, Toru whale Japanese utility knife
  • Whale-shaped Japanese utility knives made with SK5 steel. SK5 is a common Japanese tool steel.
  • Makko and Mink styled whale-shaped Japanese utility knives by Yamashita, Toru.
  • Makko and Mink styled whale-shaped utility knives on a stone surface.
Toru Yamashita // Kujira Whale Utility Knife // Makko

Toru Yamashita // Kujira Whale Utility Knife // Makko

$50.00 USD
Shipping calculated at checkout.

This whale-shaped Japanese utility knife is crafted from SK5 carbon steel, valued for its excellent sharpness, strong edge retention, and easy sharpening. Lightweight and compact, it is designed for effortless handling, making it a practical choice for everyday use as well as a distinctive addition to any knife collection.

Styled as a kogatana-style utility knife, it is ideal for precision tasks such as trimming, peeling, light food prep, opening packages, and detailed cutting work. Its small size and controlled blade profile provide accuracy and comfort, whether used in the kitchen, at a workbench, or as a desk knife.

Product Specifications:

  • Knife Shape: Kogatana-style Japanese utility knife

  • Blade Length: 47mm

  • Blade Height: 20mm

  • Blade Thickness: 3.3mm

  • Weight: 63.9g

  • Blade Construction: Warikomi

  • Cladding: Iron clad (fully reactive)

  • Core Steel: SK5 high-carbon steel

  • Hardness: ~58 HRC

  • Handle: Integrated body (no separate handle)

  • Brand: Toru Yamashita

  • Origin: Handcrafted in Tosa, Kochi, Japan

SK5 is a high-carbon Japanese tool steel commonly used for knives, woodworking tools, and blades that require strong edge retention and toughness. Its relatively simple composition allows it to achieve high hardness while remaining easy to sharpen.

Typical Chemical Composition:

  • Carbon (C): 0.80–0.90%
    Provides hardness, sharpness, and edge retention

  • Manganese (Mn): 0.30–0.50%
    Improves hardenability and toughness

  • Silicon (Si): 0.10–0.35%
    Enhances strength and elasticity

  • Phosphorus (P): ≤ 0.030%
    Kept low to reduce brittleness

  • Sulfur (S): ≤ 0.030%
    Minimized to maintain toughness

Key Characteristics of SK5 Steel:

  • High carbon content enables excellent sharpness and edge retention

  • Can be heat treated to high hardness levels

  • Easy to sharpen compared to many alloy steels

  • Lower corrosion resistance than stainless steels, requiring proper care and drying after use

  • Well suited for utility knives, kitchen tools, and traditional Japanese blades

SK5 is often compared to White #2 (Shirogami #2) in performance, offering a slightly tougher, more forgiving feel while still delivering strong cutting performance when properly heat treated.

Key Features:

  • Whale-shaped Japanese utility knife with playful yet functional design

  • SK5 high-carbon steel blade offers excellent sharpness, edge retention, and easy sharpening

  • Kogatana-style profile ideal for controlled, precise cutting tasks

  • Warikomi construction with iron cladding for strength and traditional feel

  • Compact and lightweight design for effortless handling and accuracy

  • Thick spine and rigid blade provide stability for detailed work

  • Fully reactive carbon steel develops natural patina with use

  • Handcrafted by Toru Yamashita in Tosa, Japan, a region known for traditional blades

Recommended Uses:

  • Precision utility cutting and detail work

  • Trimming, peeling, and light food preparation

  • Opening packages and everyday household tasks

  • Desk knife or workshop utility blade

  • Collectors seeking unique Japanese knife designs

  • Users who enjoy traditional carbon steel performance