Japanese Natural Whetstone Okudono Tomae 350g Selected by Yamamoto for Razors

This is a natural Japanese finishing whetstone, Okudono Tomae (奥殿 戸前), from the famous Umegahata area of Kyoto, one of the historic centers of high-quality Japanese natural whetstone production.

Okudono / Okudo (奥殿) is one of the best-known names among Kyoto JNATs. Stones from this source are highly regarded for their combination of fine abrasive structure, good cutting speed and high-quality finishing characteristics.

Tomae (戸前) is one of the classic layers associated with Japanese natural finishing stones. High-quality Tomae stones are known for their dense, homogeneous structure, consistent sharpening characteristics and ability to produce an exceptionally clean cutting edge.

Characteristics of This Stone

This stone has an attractive cool blue-grey / dark Asagi-type coloration and a very dense, visually uniform structure.

With a hardness of approximately 4/5, it is hard enough to produce a very fine finish without being excessively hard. This makes the stone comfortable and versatile to use.

Its approximate fineness is around #10000. As with all JNATs, this grit rating is only an approximate equivalent, since the actual finish depends on the steel, sharpening pressure, amount of water and slurry used.

The stone is particularly well suited for the final honing and polishing of straight razors, Japanese woodworking tools and high-quality kitchen knives, especially those made from carbon steel.

Working with Slurry

Okudono Tomae can be used directly with water, although a Nagura or Tomo Nagura can help raise slurry more quickly and allow better control over the stone's cutting action.

For straight razors, a progressive Nagura method can be especially effective: the initial slurry increases cutting speed, after which it can gradually be diluted before completing the final honing directly on the clean Okudono surface.

With proper technique, the stone is capable of producing an extremely fine, clean and highly controlled cutting edge.

Inscriptions and Stamps

A vertical inscription is clearly visible on the working surface:

戸前 奥殿 — Tomae / Okudono

This identifies the Tomae (戸前) layer and the Okudono / Okudo (奥殿) origin.

At the top of the stone there is also a special traditional stamp associated with the Kyoto natural whetstone trade. The preservation of original markings adds further interest for collectors of Japanese natural whetstones.

Yamamoto / Nakakatsu Stamp

A blue stamp is preserved on the reverse and side of the stone:

梅ケ畑砥石 中勝 山本男系山主精選

The inscription can be interpreted as follows:

梅ケ畑砥石 — Umegahata Toishi — whetstone from Umegahata, Kyoto's historic natural whetstone-producing district.

中勝 — Nakakatsu — seller / trade marking of Nakakatsu.

山本男系山主精選 — Yamamoto Danke Yamanushi Seisen — carefully selected by the Yamamoto family, representing the male lineage of whetstone mountain/mine owners.

The presence of the 山本男系山主精選 stamp is particularly valuable. It indicates that the stone was selected by the Yamamoto family, historically associated with natural whetstone mining in the Umegahata area.

奥殿 — Okudo / Okudono — designation of the Okudo quarry/mine.

Thus, this particular stone preserves an impressive group of original markings: Okudono (奥殿), Tomae (戸前), Yamamoto (山本男系山主精選) and Nakakatsu (中勝). This makes it particularly attractive both as a high-quality working JNAT and as a collectible Japanese natural whetstone.

Specifications

• Name: Okudono Tomae
• Kanji: 奥殿 戸前
• Type: Japanese Natural Finishing Whetstone — JNAT / Awasedo
• Origin: Umegahata, Kyoto, Japan
• Layer: Tomae (戸前)
• Dimensions: 165 × 55 × 16 mm
• Weight: 350 g
• Hardness: 4 / 5
• Approximate fineness: #10000
• Color: cool blue-grey / Asagi-type
• Nagura: not required, but recommended for faster slurry development
• Recommended for: straight razors, planes, chisels, Japanese and European kitchen knives

Okudono Tomae is a high-grade JNAT for users seeking an exceptionally fine finish without extreme hardness. Its combination of approximately 4/5 hardness, #10000-level fineness and original Yamamoto / Nakakatsu markings makes this stone particularly appealing both as a practical sharpening tool and as a collectible Japanese natural whetstone.