Sakai Takayuki Tokujou Unagi Saki 195 mm White 2 Carbon Steel

The Sakai cutlery association lists four regional types of unagi-saki (うなぎ裂包丁): Osaka, Kyoto, Edo and Nagoya or Ise.

A knife maker's guide describes them: the Edo type opens the eel from the back using its tip, the Kyoto type is small and shaped like a hatchet and opens the belly, and the Osaka type, close to a carving chisel with no handle, opens the belly too. The Nagoya type is long, thin and rectangular, with the tip of the spine rounded so it does not damage the eel.

Shirogami 1 (White 1) has more carbon than Shirogami 2 (White 2): Proterial lists 1.25 to 1.35% carbon for Shirogami 1 and 1.05 to 1.15% for Shirogami 2, with the same silicon (0.10 to 0.20%) and manganese (0.20 to 0.30%) ranges for both.

Proterial describes both as carbon steel with minimum impurities, Shirogami 1 with the highest hardness and Shirogami 2 with high hardness, and gives a hardening hardness of over 60 HRC for both. It lists Shirogami 1 for the highest quality tipped tools, planes, chisels and razors, and Shirogami 2 for high quality tipped tools, chisels, razors, sickles, axes and gravers.

White 1, White 2 and White 3 are Proterial's Shirogami 1, Shirogami 2 and Shirogami 3. Proterial lists carbon at 1.25 to 1.35% for Shirogami 1, 1.05 to 1.15% for Shirogami 2 and 0.80 to 0.90% for Shirogami 3, with the same silicon and manganese ranges for all three and no chromium listed.

Proterial describes all three as carbon steel with minimum impurities, at highest, high and middle hardness in that order, and gives a hardening hardness of over 60 HRC for each.

Proterial lists 1.05 to 1.15% carbon for both steels; its Blue 2 table lists 0.20 to 0.50% chromium and 1.00 to 1.50% tungsten, while its White 2 table lists neither.

Proterial describes White 2 as a carbon steel with minimum impurities and high hardness, and Blue 2 as an alloy steel with tungsten and chromium to improve heat-treatment properties and wear resistance, with a hardening hardness of over 60 HRC for both. In its Japanese materials, Proterial calls its Aogami (青紙) steels high-carbon steel (高炭素鋼). Neither steel is close to the JSSA's 10.5% minimum for stainless.

Sakai Takayuki (堺孝行) is a brand of Aoki Hamono Seisakusho (青木刃物製作所) in Sakai, Osaka, and the company's own page says so directly. The trademarks for 堺孝行 and 堺菊孝 were registered in 1964.

The company started in Osaka in 1947 as a wholesaler of Sakai forged knives, set up a sales office in Sakai in 1963, and built a factory in Sakai in 1977. So when you see the Sakai Takayuki name, that is Aoki Hamono's own line.

Sakai Takayuki knives are made by Aoki Hamono Seisakusho and its craftsmen in Sakai, Osaka. The company's own traditional-craftsman page profiles its named Sakai smiths.

Aoki Hamono's own page says Sakai knives are made by division of labour: blacksmiths forge the blade, and sharpening craftsmen then grind and sharpen it. Aoki Hamono's Sanpou factory, home to its smiths and sharpeners since 1978, added an automatic grinding machine for Japanese knives in 2015.

A honyaki is water quenched with sword-style hardening, so it usually runs about 1 to 2 HRC harder than a comparable knife that is not honyaki, though that varies by maker. The quench has a high failure rate, and that craft is a large part of the price.

A honyaki also needs more care. If your kitchen is busy, an everyday line such as the 33-layer or 45-layer VG10 Damascus, which share a VG10 core and differ mostly in looks, is the easier choice; if you want a harder edge and the craft itself, a honyaki can suit you.