Hatsukokoro x Satoshi Nakagawa Blue 1 Damascus Sujihiki 240mm

Between 210 and 270 mm, depending on where it will work. One Japanese maker lists 210 to 240 mm, double-bevel, for home use and 240 to 270 mm, single- or double-bevel, for professional kitchens.

Another, in Sakai, recommends 240 mm at home, with the size of your board in mind, and 270 mm for professional use.

A sujihiki is a long, double-bevel knife for dividing larger pieces of meat into their parts, and its length lets it slice sashimi too; a yanagiba is the sashimi knife.

The Sakai cutlery association describes the yanagiba (柳刃包丁) edge as so acute that it cannot be used on bone or other hard things, so choose the sujihiki for meat and the yanagiba if sashimi is the main job.

Yes, carbon steels such as Aogami (Blue) and Shirogami (White) are not stainless steels, so left wet they can spot or rust.

Care is simple once it becomes habit. Wipe the blade as you go, especially after acidic food like citrus, tomato or onion. When you finish, wash it in warm water with a little soap and dry it straight away with a towel. Do not let it air dry, leave it in the sink or the dish rack, or put it in the dishwasher. Store it dry: on a magnetic strip, in a saya or in a block in a dry spot.

If the knife will sit unused for a while, wipe on a thin layer of oil before storing. In our video James shows that mineral oil can stand in for camellia (tsubaki) oil, and he picks one labelled medical grade; we list the Kitchen Knife / Cutting Board Mineral Oil Medical Grade for this. If you find light rust, lift it with a rust eraser and a little water, then dry and oil the blade; we list the CKK and Naniwa rust erasers.

Proterial, which makes both, describes each the same way: an alloy steel with tungsten and chromium added to improve heat-treatment properties and wear resistance, hardening to over 60 HRC. In its Japanese materials, Proterial calls its Aogami (青紙) steels high-carbon steel (高炭素鋼).

Its figures give Blue 1 more carbon and tungsten, 1.25 to 1.35% carbon and 1.50 to 2.00% tungsten against Blue 2's 1.05 to 1.15% and 1.00 to 1.50%, with chromium of 0.30 to 0.50% against 0.20 to 0.50%.

Yes. Our line page lists a Blue 1 core with soft iron Damascus cladding, and that cladding is not stainless.

Proterial lists Blue 1 chromium at 0.30 to 0.50%, well under the 10.5% the JSSA sets for stainless. We suggest wiping the whole blade dry after washing, not just the edge.

Pick by how much care you want to give. Ginsan is stainless, while Blue 1 and Blue 2 are not: Proterial lists their chromium at 0.50% or less, well under the 10.5% the Japan Stainless Steel Association sets for stainless.

If you will dry and oil the blade after each use, a Blue 1 or Blue 2 line can suit you; if you want less upkeep, we suggest Ginsan.

Yes. We know from our own dealings with him that Satoshi Nakagawa forges commissioned lines for the Hatsukokoro brand, and our product titles name them Hatsukokoro by Nakagawa and Hatsukokoro x Nakagawa. He works from his own company in Sakai, Nakagawa Uchihamono.

He trained for sixteen years under Kenichi Shiraki as his only disciple and successor. His company says he works in White 3 to White 1, Blue 2 to Blue 1, stainless Ginsan, VG10 and honyaki.