Is Blue steel better than White steel?

Not simply. Blue steel adds tungsten and a little chromium to the same carbon levels, which the maker says improves wear resistance. White steel is the plainer carbon steel. Which suits you depends on how you sharpen and use the knife.

No. Aogami contains only 0.20–0.50% chromium, far below the roughly 10.5% needed for a stainless steel. It rusts if left wet, like Shirogami.

What do Shirogami and Aogami mean?

In Japanese, Shirogami means “white paper” and Aogami “blue paper”. In English they are usually called White steel and Blue steel, or White Paper and Blue Paper steel.

Are White #2 and Blue #2 the same hardness?

Proterial publishes the same hardening hardness of 60 HRC or over for both. The hardness of a finished knife depends on the knifemaker’s heat treatment.

Blue Steel vs White Steel (Aogami vs Shirogami): The Real Difference

Steel comparison · maker data checked 2026-10-21Blue vs White steel

Grade for grade, Blue and White steel have the same carbon — Aogami #1 and Shirogami #1 both have 1.25–1.35%, #2 both 1.05–1.15%. The difference is that Blue steel adds 1.0–2.5% tungsten and 0.2–0.5% chromium, which Proterial says improves heat-treatment properties and wear resistance. Neither is stainless; both must be dried after use.

Side by side

	Shirogami #1	Aogami #1	Shirogami #2	Aogami #2	Shirogami #3	Aogami Super
Maker	Proterial	Proterial	Proterial	Proterial	Proterial	Proterial
Type	Carbon	Carbon	Carbon	Carbon	Carbon	Carbon
Stainless	No	No	No	No	No	No
C %	1.25–1.35	1.25–1.35	1.05–1.15	1.05–1.15	0.80–0.90	1.40–1.50
Si %	0.10–0.20	0.10–0.20	0.10–0.20	0.10–0.20	0.10–0.20	0.10–0.20
Mn %	0.20–0.30	0.20–0.30	0.20–0.30	0.20–0.30	0.20–0.30	0.20–0.30
Cr %	—	0.30–0.50	—	0.20–0.50	—	0.30–0.50
W %	—	1.50–2.00	—	1.00–1.50	—	2.00–2.50
V %	—	—	—	—	—	0.30–0.50
P %	≤0.025	≤0.025	≤0.025	≤0.025	≤0.025	≤0.025
S %	≤0.004	≤0.004	≤0.004	≤0.004	≤0.004	≤0.004
Maker HRC	≥60	≥60	≥60	≥60	≥60 water-quenched; ≥52 oil-quenched and tempered at 280–340 °C	≥60
CATRA mm	not tested	not tested	not tested	not tested	not tested	338 @ 65.1 HRC

Mass %, steelmakers’ published typical or representative values. † retailer values (the maker does not publish them). Maker HRC is the hardening hardness the steelmaker publishes, not the hardness of a finished knife. CATRA: Knife Steel Nerds edge-retention test, total card cut. PM = powder metallurgy.

What the data says

Both families are made by Proterial (formerly Hitachi Metals) as part of its Yasugi Specialty Steel (YSS) range. In Japanese, Shirogami means “white paper” and Aogami “blue paper”.
Proterial describes the White steels as carbon steel with minimum impurities, and the Blue steels as alloy steel with tungsten and chromium added to improve heat-treatment properties and wear resistance.
The numbered grades pair up by carbon: Shirogami #1 and Aogami #1 share 1.25–1.35% carbon, and Shirogami #2 and Aogami #2 share 1.05–1.15%. Aogami Super has more carbon (1.40–1.50%), more tungsten (2.00–2.50%) and adds vanadium. Shirogami #3, at 0.80–0.90% carbon, has no Blue counterpart.
The chromium in Blue steel (0.20–0.50%) is far below the roughly 10.5% that makes a steel stainless, so Blue steel rusts like White steel and forms a patina with use.
Proterial publishes the same hardening hardness — 60 HRC or over — for all of these grades. Higher numbers quoted by shops describe a particular knifemaker’s heat treatment.
Of the six, only Aogami Super has been tested in Knife Steel Nerds’ CATRA edge-retention test (338 mm of card at 65.1 HRC). There is no independent test result comparing a White steel with its Blue counterpart, so claims that one “holds an edge X times longer” are not backed by published data that we could find.
A common view among knife shops and sharpeners is that White steel is easier to sharpen and Blue steel holds its edge longer. We have not found a controlled test of the sharpening part, so treat it as craft opinion; the edge-holding part is consistent with the maker’s description of improved wear resistance.

Which should you choose?

If…	Look at
You want the simplest carbon steel, as the maker describes it, with minimal impurities	Shirogami #1 or #2
You want the maker’s added wear resistance from tungsten	Aogami #1 or #2
You want the most carbon and alloying of the paper steels	Aogami Super
You do not want to dry the knife after every use	Neither — look at a stainless steel such as Ginsan or VG-10

The steel is only part of a knife: the knifemaker’s heat treatment, the blade geometry and the edge angle matter as much. See all steels in the Japanese knife steel chart, and if you are ordering from Japan, check the import duty calculator first.

Frequently asked questions

Is Blue steel better than White steel?: Not simply. Blue steel adds tungsten and a little chromium to the same carbon levels, which the maker says improves wear resistance. White steel is the plainer carbon steel. Which suits you depends on how you sharpen and use the knife.
Is Aogami stainless?: No. Aogami contains only 0.20–0.50% chromium, far below the roughly 10.5% needed for a stainless steel. It rusts if left wet, like Shirogami.
What do Shirogami and Aogami mean?: In Japanese, Shirogami means “white paper” and Aogami “blue paper”. In English they are usually called White steel and Blue steel, or White Paper and Blue Paper steel.
Are White #2 and Blue #2 the same hardness?: Proterial publishes the same hardening hardness of 60 HRC or over for both. The hardness of a finished knife depends on the knifemaker’s heat treatment.

More comparisons

Sources

Checked 2026-10-21. Found a better source or an error? Tell us.