白紙と青紙
Blue steel is white steel with alloys added. It holds an edge longer and is harder to bring back — which makes the better choice depend on how often you sharpen, not on which steel is finer.
Japanese Knife Lab sets out the difference: Aogami — blue steel — adds chromium and tungsten to the carbon steel formula, giving better edge retention and slightly more toughness, with Aogami Super pushing edge life further still. The trade-off it names is that blue steel is slightly harder to sharpen and does not reach quite the same ultimate keenness as white.
So the alloyed steel is not the upgrade the price order suggests. The same source says professional sushi chefs who sharpen daily overwhelmingly prefer white steel for the purest cutting feel — because when sharpening is routine, edge retention buys you little and ease of sharpening buys you a lot. Reverse those conditions and the answer reverses with them.
Neither is stainless. SharpEdge, describing a Shirogami 2 blade, notes that the steel contains no chromium and will develop patina in use; blue steel adds some chromium but not nearly enough to make it stainless, so both still want drying after every use. The choice between them is about sharpening, not about maintenance — that part is the same either way.
A listing that names the steel — Shirogami 2, Aogami 2, Aogami Super — has told you something useful; one that says only “high carbon Japanese steel” has not. Where a hardness figure is given it is worth reading too: the Shirogami 2 blade cited below is stated at 61–62 HRC, and a listing willing to publish that number is generally willing to publish the rest. What no listing decides for you is how often you will sharpen, which is the question this page turns on.
There is no shop link here. Recommending a steel would mean assuming an answer to that question. The guides below cover what to sharpen on, and what the discolouration means once the blade is in use.
Sources The other guides鉄瓶と鉄急須
One boils water and gives you iron. Putting the other on heat cracks its lining for good.
土鍋の目止め
Unglazed clay is porous until rice starch seals it — one simmer, once.
漆器の手入れ
Dishwasher, microwave, sunlight. All normal, all irreversible on urushi.
片刃と利き手
Ground on one side only. The wrong side does not cut badly — it does not work.
土鍋とIH
Induction heats metal, not clay. Most donabe never get warm — and cannot be converted.
熊野筆の毛
Not a quality ladder. Natural hair holds powder; synthetic is built for cream and liquid.
砥石の番手
There is no dominant standard behind the number. Two #1000 stones can cut differently.
茶筅の穂数
Carved from a single piece, so a snapped tine is not a repair. The tine count is a spec, not a score.
錆と経年変化
One protects the blade, the other eats it. Scrubbing the wrong one leaves the knife worse off.
三徳・牛刀・菜切
Two of these are the same knife. And a nakiri suits either hand; the usuba it resembles does not.
ダマスカスの意味
The original ceased production around 1900. Since 1973 the word has meant pattern welding — decoration.
抹茶の等級表示
ISO and Japanese labelling define how matcha is made. Neither defines a grade.
硬度と刃角
Western knives sit at 52–58 and 20–22°; harder steel is what permits 15–18°. Higher is a different bargain.
まな板と刃
Glass dents, rolls and chips edges rapidly. Wood is self-healing — but grain matters more than "hardwood".
刃物を贈るとき
A gifted knife is said to sever the relationship. The custom is that the recipient hands back a coin.
金継ぎのキット
Real urushi cures in a humid box over days to weeks. A kit that sets in an hour is something else.
沈香と伽羅
The scent exists because the tree was infected. Uninfected wood is pale and light — whatever was added.
箸の形と作法
Pointed where Chinese ones are blunt. And two ordinary gestures read as funeral rites.