Semi-Stainless
Semi-Stainless Steel
Semi-stainless steels sit between carbon and full stainless. They will rust if left wet or neglected, but under normal use they tend to develop a patina — a dark, protective layer — rather than forming aggressive surface rust. Rinse and wipe dry after use and you will rarely have issues. Much more forgiving than true carbon steel, while still offering excellent cutting performance. Hitachi Special Steel, Japan 🇯🇵
Semi-stainless steels sit between carbon and full stainless. They will rust if left wet or neglected, but under normal use they tend to develop a patina — a dark, protective layer — rather than forming aggressive surface rust. Rinse and wipe dry after use and you will rarely have issues. Much more forgiving than true carbon steel, while still offering excellent cutting performance. Hitachi Special Steel, Japan 🇯🇵
SLD SLD鋼
Hardness
Rockwell C Hardness(HRC) measures how resistant a steel is to permanent deformation. For kitchen knives:
55–58 HRC — Soft. Easy to sharpen and forgiving of rough use, but dulls faster. Typical of most German knives.
59–61 HRC — Balanced. Good edge retention with manageable sharpening. Common in mid-range Japanese knives.
62–64 HRC — Hard. Excellent edge retention, holds a very fine edge. Requires more care and a fine stone to sharpen.
65+ HRC — Very hard. Exceptional edge longevity but more brittle — more prone to chipping if used roughly.
Higher is not always better — it depends on how you use and maintain your knife.
55–58 HRC — Soft. Easy to sharpen and forgiving of rough use, but dulls faster. Typical of most German knives.
59–61 HRC — Balanced. Good edge retention with manageable sharpening. Common in mid-range Japanese knives.
62–64 HRC — Hard. Excellent edge retention, holds a very fine edge. Requires more care and a fine stone to sharpen.
65+ HRC — Very hard. Exceptional edge longevity but more brittle — more prone to chipping if used roughly.
Higher is not always better — it depends on how you use and maintain your knife.
62–64
HRC
555759616365+
Hitachi SLD steel is a tool steel designed originally for die and machining tools. Its composition is practically identical to the D2 tool steel - a classic steel that have withstands the test of time since the WW2. The high level of Chromium content in it have made this steel almost stainless, and the decent amount of Molybdenum and Vanadium forms hard carbide, given this steel a pretty good edge retention. The toughness may be average of its kind, but it shouldn't be a big concern under the condition of normal kitchen use. SLD steel would be a good choice for those who are looking for a steel that can develop a keen edge, but not as attention demanding as a classic carbon steel.
Composition
SLD Element Composition
Compare with
SLD
—
12.0%
9.0%
6.0%
3.0%
0
C
1.5%
Cr
12.0%
V
0.3%
Mo
0.9%
Mn
0.4%
Si
0.3%
C — Carbon
Cr — Chromium
V — Vanadium
Mo — Molybdenum
Mn — Manganese
Si — Silicon
Typical values from third-party sources.
Hardness
62–64 HRC
555759616365+
SLD Composition
What's in SLD
What each element does in your knife.
| Element | Composition | What it does in your knife |
|---|---|---|
| CCarbon | 1.5% | The primary hardening element. More carbon means a harder edge that holds longer — but past a point it trades away toughness and rust resistance. |
| SiSilicon | 0.3% | Strengthens the steel matrix and acts as a deoxidiser, improving hardness and resistance to oxidation. |
| MnManganese | 0.4% | Aids hardenability and strength and acts as a deoxidiser in smelting. Too much can reduce toughness. |
| CrChromium | 12.0% | Raises corrosion resistance; at roughly 13%+ free chromium the steel qualifies as stainless. Also improves hardenability and wear. |
| MoMolybdenum | 0.9% | Improves hardenability and toughness, boosts corrosion resistance, and helps the steel hold hardness under heat. |
| VVanadium | 0.3% | Forms extremely hard vanadium carbides for superior edge retention, and refines the grain for a finer, tougher edge. |
Composition per Proterial's representative analysis (https://www.proterial.com/e/yss/search/sld.html; fetched 2026-09-21). Proterial publishes these as typical values for its YSS grade, not a guaranteed range.
Knives in SLD
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Sale
Knives and Stones (K&S)
K&S Yuepo SLD Nashiji Sujihiki 270mm, Ebony Handle
Sale
Knives and Stones (K&S)
K&S Yuepo SLD Nashiji Gyuto 240mm, Ebony Handle
Sale
Knives and Stones (K&S)
K&S Yuepo SLD Nashiji Gyuto 210mm, Ebony Handle
Sale
Knives and Stones (K&S)
K&S Yuepo SLD Nashiji K-tip Gyuto 210mm, Ebony Handle
Sale
Knives and Stones (K&S)
K&S Yuepo SLD Nashiji Bunka 180mm, Ebony Handle
Sale
Knives and Stones (K&S)
K&S Yuepo SLD Nashiji Santoku 180mm, Ebony Handle
Sale
Knives and Stones (K&S)
K&S Yuepo SLD Nashiji Ko-Santoku 135mm, Ebony Handle
Sold Out
Hatsukokoro
Hatsukokoro x Nigara Yorokobi SLD Copper Damascus Sujihiki 450mm Amboyna Triple Spacer Handle RARE
Tsunehisa
Tsunehisa SLD Washiji Santoku 170mm Burnt Kashi
Hatsukokoro
Hatsukokoro Hikari SLD Damascus K-tip Petty 120mm
Hatsukokoro
Hatsukokoro Hikari SLD Damascus Nakiri 170mm
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Nigara
Hatsukokoro x Nigara Yorokobi Full Polish SLD K-tip Gyuto 210mm Black Damascus Birch
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi Full Polish SLD Gyuto 210mm Black Damascus Birch
Sold Out
Hatsukokoro
Hatsukokoro Hikari SLD Damascus Petty 130mm
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Hatsukokoro
Hatsukokoro Hikari SLD Damascus Petty 150mm
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Hatsukokoro
Hatsukokoro Hikari SLD Damascus Santoku 170mm
Hatsukokoro
Hatsukokoro Hikari SLD Damascus Gyuto 195mm Black Chacate
Hatsukokoro
Hatsukokoro Hikari SLD Damascus Gyuto 210mm
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HADO
Hado Ouru SLD Nashiji K-tip Gyuto 200mm
Sold Out
HADO
Hado Ouru SLD Nashiji Ko-Bunka 135mm
Sold Out
Hatsukokoro
Hatsukokoro Hikari SLD Gyuto 210mm Black Chacate
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi Special SLD Kurouchi Damascus K tip Gyuto 240mm Polished
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi Special SLD Kurouchi Damascus Bunka Polished
Hatsukokoro
Hatsukokoro Hikari SLD Nakiri 165mm Black Chacate
Sold Out
Tsunehisa
Tsunehisa SLD Washiji Gyuto 210mm Burnt Kashi
Sold Out
Hatsukokoro
Hatsukokoro Hikari SLD Santoku 170mm
Sold Out
Hatsukokoro
Hatsukokoro Hikari SLD Gyuto 195mm Black Chacate
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi SLD Copper Tsuchime Damascus Petty 150mm with Saya
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi SLD Copper Tsuchime Damascus K tip Gyuto 240mm with Saya
Nigara
Hatsukokoro x Nigara Yorokobi Special SLD Gyuto 210mm Kurouchi Damascus Birch Handle
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi Special SLD K-tip Gyuto 210mm Kurouchi Damascus Birch Handle
Nigara
Hatsukokoro x Nigara Yorokobi Special SLD Kurouchi Damascus K tip Gyuto 240mm Birch Handle
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi SLD Copper Tsuchime Damascus Gyuto 240mm with Saya
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi SLD Copper Tsuchime Damascus Bunka 180mm Birch Handle
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi SLD Copper Tsuchime Damascus Santoku 180mm with Saya
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi Special SLD Kurouchi Damascus Gyuto 240mm Birch Handle
Sold Out
Hatsukokoro
Hatsukokoro x Nigara Yorokobi SLD Copper Damascus Sujihiki 270mm Birch Handle
Sold Out
Hatsukokoro
Hatsukokoro x Nigara Yorokobi SLD Copper Damascus Sujihiki 240mm Birch Handle
Sold Out
Nigara
Hatsukokoro x Nigara Yorokobi Special SLD Kurouchi Damascus Santoku
Sold Out
Hatsukokoro
Hatsukokoro x Nigara Yorokobi SLD Copper Damascus Santoku 180mm Birch Handle
Sold Out
Hatsukokoro
Hatsukokoro x Nigara Yorokobi SLD Copper Damascus Bunka 180mm Birch Handle
Sold Out
Hatsukokoro
Hatsukokoro x Nigara Yorokobi SLD Copper Damascus K-tip Gyuto 240mm Birch Handle
Sold Out
Hatsukokoro
Hatsukokoro x Nigara Yorokobi SLD Copper Damascus K-tip Gyuto 210mm Birch Handle
Sold Out
Hatsukokoro
Hatsukokoro x Nigara Yorokobi SLD Copper Damascus Gyuto 240mm Birch Handle
Sold Out
Hatsukokoro
