The honest guide to Japanese knife steels

How to actually read this guide

Every steel below is good. Nothing here is a ranking, because steel choice is a set of trade-offs between four things: how keen an edge it takes, how long it holds it, how easily it sharpens, and how much care it demands. Smiths choose steels the way cooks choose ingredients — for what they're making, not for a leaderboard. Your job is just to be honest about your kitchen.

One framing that helps: hardness (HRC) is a dial, not a score. Push it up and the edge lives longer but chips easier and sharpens slower. The numbers below are typical ranges as the makers we work with run them.

The carbon classics

White #2 · Shirogami 2 · 白二

The purist's steel: extremely pure carbon steel that takes the keenest edge of anything here and sharpens fast and sweetly on stones. It rusts if neglected and its edge, while screaming sharp, needs more frequent touch-ups. This is the steel of the Sakai single-bevel tradition — Masamoto's KS line and most classic yanagiba — and the steel honyaki masters stake their reputations on. ~61–64 HRC.

White #1 · Shirogami 1 · 白一

White #2 with more carbon: harder, keener, less forgiving — for the cook who already keeps stones wet. Masamoto's KI tier is the reference point. ~62–65 HRC.

Blue #2 · Aogami 2 · 青二

White steel plus tungsten and chromium: noticeably better edge retention and a little more toughness, for slightly more effort on the stones. The workhorse of serious carbon knives — much of the Sanjo tradition runs on it. ~62–64 HRC.

Blue Super · Aogami Super

The hot-rodded carbon: more of everything, including hardness (~63–65 HRC) and retention approaching the powder steels, while still sharpening like a carbon steel. Sukenari and Kisuke Manaka both do celebrated work in it. Reactive — the wipe-dry habit applies.

The stainless that feels traditional

Ginsan · Silver #3 · 銀三

The answer to "I want carbon-steel feel without the rust." Ginsan is a fine-grained stainless that sharpens almost like White steel and takes a genuinely keen edge — which is why Sakai smiths reach for it when sushi chefs ask for stainless, and why Nakagawa-san's Ginsan work is so respected. ~61–62 HRC. If your first serious knife must be stainless, start here.

VG10

The most common premium stainless in Japanese knives — reliable, corrosion-proof, takes a good edge, holds it respectably. It's the core of Takeshi Saji's Rainbow Damascus among countless others. Less charming on the stones than Ginsan; more forgiving everywhere else. ~60–61 HRC.

The powder steels

SG2 / R2

Powder metallurgy makes steel the way espresso makes coffee: fine, even, intense. SG2 is the practical face of it — stainless, ~62–63 HRC, edge retention well beyond VG10, and still sharpenable by a patient amateur. The sweet spot for a low-maintenance knife that performs at carbon level day to day.

ZDP-189

The extremist's stainless: around 3% carbon and hardness at 65–67 HRC, edge retention measured in weeks of service. The catch: it is genuinely difficult to sharpen and so hard to forge that very few smiths work it at all — Sukenari built part of its reputation on being one of them. Choose it knowing what you're signing up for on the stones.

HAP40

A high-speed tool steel, semi-stainless, ~64–66 HRC — many enthusiasts' pick for the best retention-to-toughness balance among the super steels. Patinas slightly; sharpens hard but rewards it. Another Sukenari speciality.

The honest decision guide

You are…	Choose	Because
New to serious knives, busy kitchen	Ginsan or SG2	Stainless forgiveness, real performance, learnable sharpening.
In love with sharpening	White #2	The keenest edge and the most rewarding stones in the craft.
Wanting carbon with longer legs	Blue #2 / Blue Super	Retention without giving up the carbon feel.
Chasing maximum retention, eyes open	ZDP-189 or HAP40	Weeks-long edges, priced in sharpening effort.
Heading toward single bevels / honyaki	White #1 / #2	The traditional path — read our honyaki guide first.

And the rule that overrides the table: the right steel is the one whose care you'll actually do. A wiped-down White #2 outlives a neglected SG2's owner's enthusiasm every time — and the reverse is just as true. Be honest about your kitchen, and the steel chooses itself.

Questions we're actually asked

What is the best steel for a Japanese kitchen knife?

There isn't one — there's a best steel for your habits. White #2 for the purist who enjoys sharpening, Blue #2 for retention with traditional feel, Ginsan or SG2 if you want stainless, ZDP-189 or HAP40 if you want maximum retention and accept harder sharpening.

Is carbon steel hard to look after?

It needs a habit, not a skill: wipe the blade dry as you work and before it's put away. The reward is the keenest edges and the easiest sharpening. If the habit won't survive your kitchen, choose stainless honestly — Ginsan feels closest to carbon.

What does HRC hardness actually mean?

Rockwell hardness measures resistance to deformation. Higher numbers (63–67) hold an edge longer but chip more easily and take longer to sharpen; lower numbers (58–61) trade retention for toughness. It's a trade-off dial, not a quality score.

Are powder steels like SG2 and ZDP-189 better than traditional steels?

Better at retention, usually; worse on the stones, always. Powder metallurgy gives fine, even carbide structure at very high hardness. Traditional White and Blue steels sharpen faster and take a keener apex. Different virtues for different cooks.

Which steel should my first serious Japanese knife be?

For most people: Ginsan or SG2 — stainless enough to forgive a busy kitchen, hard enough to show you what the fuss is about. If you know you'll enjoy the ritual, White #2 teaches you more.